question

Chemical kinetics

answer

how the molecular world changes with time

question

Thermal

answer

__ energy produces constant molecular motion, causing molecules to repeatedly collide with one another.

question

-nuclei
-kinetics

answer

In a small fraction of the collisions caused by thermal energy, the electrons on one molecule or atom are attracted to the __ of another. Some bonds weaken and new bonds form – a chemical reaction occurs. Chemical __ is the study of how these kinds of changes occur in time

question

Rate of reaction

answer

__ = how fast a reaction occurs

question

life

answer

Reaction rates are important to __

question

enzymes

answer

Rate of reaction is controlled through the use of __

question

Wilhelmy

answer

__ = first person to measure the rate of a chemical reaction

question

molecular

answer

The rate of a reaction can tell us much about how the reaction occurs on the __ scale

question

reaction

answer

The rate of a chemical reaction is a measure of how fast the __ occurs

question

Slow rate of reaction

answer

__ = small fraction of molecules react to form products in a given period of time

question

Fast rate of reaction

answer

__ = large fraction of molecules react to form products in a given period of time

question

change in some quantity per unit of time

answer

When measuring the rate at which something occurs, we express the measurement as a __

question

-measuring
-time

answer

When measuring the rate at which something occurs, we report the rate in units that represent the change in what we are __ divided by the change in __

question

-reactants or products (usually in concentration units)
-time

answer

The rate of a chemical reaction is measured as a change in the amounts of __ divided by the change in __

question

Reaction rate

answer

__ – the negative of the change in concentration of a reactant divided by the change in time

question

-reactant
-decrease

answer

The negative sign is part of the definition when the reaction rate is defined with respect to a __ because reactant concentrations __ as a reaction proceeds; therefore the change in the concentration of a reactant is negative, which makes the overall rate positive

question

positive

answer

Reaction rates are reported as __ quantities

question

product

answer

The reaction rate can also be defined with respect to the __ of the reaction

question

-increase
-positive

answer

Product concentrations __ as the reaction proceeds, the change in concentration of a product is __

question

-don’t include
- positive

answer

When the rate is defined with respect to a product, __ a negative sign – the rate is naturally __

question

stoichiometric coefficients

answer

To have a single rate for an entire reaction, the definition of the rate with respect to each reactant and product must reflect the __ of the reaction

question

-decreases
-consumed

answer

The reactant concentration __ with time because reactants are __ in a reaction

question

-increases
-formed

answer

The product concentration __ with time because products are __ in a reaction

question

Rate = - ?[molecule] / ?t

answer

Calculate the average rate of the reaction for any time interval using the equation: __

question

- decreases
-slows down

answer

The average rate __ as the reaction progresses, the reaction __ as it proceeds

question

concentrations of the reactants

answer

The average rate of the reaction depends on the __

question

-decrease
-slows down

answer

As reactants transform to products, their concentrations __, and the reaction __

question

Instantaneous rate of the reaction

answer

__ = the rate at any one point in time, and is represented by the instantaneous slope of the curve at that point

question

slope of the tangent to the curve

answer

Determine the instantaneous rate from the __ at the point of interest

question

-(1 / a)(?[A] / ?t) = -(1 / b)( ?[B] / ?t) = +(1 / c)( ?[C] / ?t) = +(1 / d)( ?[D] / ?t)

A and B

C and D

a, b, c, and d

answer

Rate of the reaction > Rate = __
__ are reactants, __ are products, and __ are the stoichiometric coefficients

question

any other reactant or product at that point in time (from the balanced equation)

answer

Knowing the rate of change in the concentration of any one reactant or product at a point in time allows us to determine the rate of change in the concentration of __

question

not possible

answer

Predicting the rate at some future time is __ from just the balanced equation

question

kinetics

answer

Must have an experimental way to measure the concentration of at least one of the reactants or products as a function of time to study the __ of a reaction

question

Polarimetry (experimental way to measure the concentration of at least one of the reactants or products as a function of time)

answer

__ – measuring the degree of polarization of light passing through a reacting solution to determine the relative concentrations of the reactants and products as a function of time

question

spectroscopy (experimental way to measure the concentration of at least one of the reactants or products as a function of time)

answer

Most common way to study the kinetics of a reaction is through __

question

Spectrometer (experimental way to measure the concentration of at least one of the reactants or products as a function of time)

answer

__ – device that passes light through a sample and measures how strongly the light is absorbed.

question

spectrometer (experimental way to measure the concentration of at least one of the reactants or products as a function of time)

answer

In using a __, if the sample contains the reacting mixture, the intensity of the light absorption will decrease as the reaction proceeds, providing a direct measure of the concentrations of the molecule as a function of time

question

pressure (experimental way to measure the concentration of at least one of the reactants or products as a function of time)

answer

Reactions in which the number of moles of gaseous reactants and products changes as the reaction proceeds can be monitored by measuring changes in __

question

-increases
-rises
-rise

answer

As a reaction proceeds and the amount of gas __, the pressure steadily __. The __ in pressure can be used to determine the relative concentrations of reactants and products as a function of time

question

polarimetry, spectroscopy, and pressure measurement

answer

Three techniques – __ – can be used to monitor the reaction as it occurs in the reaction vessel

question

progress of the reaction

answer

Some reactions occur slowly enough that samples, or aliquots can be periodically withdrawn from the reaction vessel and analyzed to determine the __

question

sample

answer

__ = aliquot

question

aliquot

answer

Instrumental techniques – gas chromatography, mass spectrometry - can be used to measure the relative amounts of reactants or products in the __

question

reactants and products

answer

Taking aliquots at regular time intervals, can determine the relative amounts of __ as a function of time

question

concentration

answer

Rate of a reaction depends on the __ of one or more of the reactants

question

rate law

answer

As long as the rate of the reverse reaction (in which the products return to reactants) is negligibly slow, we can write a relationship – called the __ – between the rate of the reaction and the concentration of the reactant

question

k[A]ⁿ

answer

Rate law equation = __

question

k = constant of proportionality called the rate constant
n = reaction order. The value of this determines how the rate depends on the concentration of the reactant

answer

in the rate law equation k[A]ⁿ , k = __, n = __

question

-zero order
- independent of the concentration of A

answer

if n = 0, the reaction is __ and the rate is __

question

-first order
-directly proportional to the concentration of A

answer

ifn = 1, the reaction is __ and the rate is __

question

-second order
-proportional to the square of the concentration of A

answer

if n = 2, the reaction is __, and the rate is __

question

concentration

answer

in a zero-order reaction, the rate of the reaction is independent of the __ of the reactant

question

k[A]⁰ = k

answer

if the reaction is a zero-order reaction, rate =

question

-decreases
-constant
-does not

answer

in a zero-order reaction,the concentration of the reactant __ linearly with time at a __ rate because the reaction ___ slow down as the concentration of A decreases

question

same

answer

The rate of a zero-order reaction is the __ at any concentration of A

question

Zero-order

answer

__ reactions occur under conditions where the amount of reactant actually available for reaction is unaffected by changes in the overall quantity of reactant

question

zero order

answer

Sublimation is normally a __ reaction because only molecules at the surface can sublime, and their concentration does not change when the amount of subliming substance decreases

question

directly proportional

answer

in a first-order reaction,the rate of the reaction is __ to the concentration of the reactant

question

k[A]¹

answer

in a first-order reaction, rate = __

question

-slows down
- decreases

answer

For first-order reaction the rate __ as the reaction proceeds because the concentration of the reactant __

question

first-order

answer

in a __ reaction,the rate is directly proportional to the concentration

question

proportional to the square

answer

in a second-order reaction,the rate of the reaction is __ of the concentration of the reactant

question

k[A]²

answer

for a second-order reaction, rate = __

question

sensitive

answer

For second-order reaction, the rate is __ to the reactant concentration

question

second-order

answer

for a __ reaction,the rate is proportional to the square of the concentration

question

experiment

answer

The order of a reaction can be determined only by __

question

Method of initial rates

answer

___ = common way to determine reaction order method of initial rates

question

the initial rate

answer

__ – the rate for a short period of time at the beginning of the reaction

question

method of inital rates

answer

the initial rate is measured by running the reaction several times with different initial reactant concentrations to determine the effect of the concentration on the rate

question

-initial rate
- initial concentration

answer

For a reaction that is a first-order reaction, the __ is directly proportional to the __

question

k[A]¹

answer

for a reaction that is a first-order reaction, Rate = __

question

solving the rate law for k and substituting the concentration and the initial rate from any one of the measurements found through experiment

answer

For a reaction that is a first-order reaction, determine the value of the rate constant, k, by __

question

s^-1

answer

For a first-order reaction, the rate constant has units of __

question

-same
-initial

answer

For a zero-order reaction, the initial rate is independent of the reactant concentration – the rate is the __ at all measured __ concentrations

question

-quadruples
-doubling
-quadratic

answer

For a second-order reaction, the initial rate __ for a __ of the reactant concentration – the relationship between concentration and rate is __

question

second-order

answer

For a __ reaction you can substitute any two initial concentrations and the corresponding initial rates into a ratio of the rate laws to determine the order (n): rate 2 / rate 1 = k[A]ⁿ₂ / k[A]ⁿ₁

question

M x s^-1

answer

The rate constant for a zero-order reaction has units of __

question

M^-1 x s^-1

answer

The rate constant for a second-order reaction has units of __

question

multiplied

answer

reaction order for multiple reactants:As long as the reverse reaction is negligibly slow, the rate law is proportional to the concentration of [A] raised to the m __ by the concentration of [B] raised to the n

question

k[A]^m[B]ⁿ

answer

Reaction order for multiple reactants; Rate = __

question

-A and B
-m
-n

answer

in the reaction order for multiple reactions,Rate = k[A]^m[B]ⁿ;
__ are reactants

__ is the reaction order with respect to A
__ is the reaction order with respect to B

question

sum of the exponents (m + n)

answer

in the reaction order for multiple reactants,the overall order is the __

question

-experiment
-method of initial rates

answer

the rate law for any reaction must always be determined by __, often by the __

question

rate law

answer

no simple way to look at a chemical equation and determine the __ for the reaction

question

independently

answer

in determining the reaction order for multiple reactants,when there are two or more reactants, the concentration of each reactant is usually varied __ of the others to determine the dependence of the rate on the concentration of that reactant

question

Integrated rate law

answer

__ for a chemical reaction is a relationship between the concentration of the reactants and time

question

order of the reaction

answer

The integrated rate law for a reaction depends on the __

question

ln[A]_t = -kt + ln[A]₀ OR ln ([A]_t / [A]₀) = -kt

answer

what is the first-order integrated rate law?

question

[A]_t
k
[A]₀

answer

for all of the integrated rate laws:
__ = the concentration of A at any time, t
__ = rate constant
__ = initial concentration of A

question

straight line
ln[A]_t = -kt + ln[A]_{0 -->}
y = mx + b

answer

the integrated rate law has the form of an equation for a __

question

straight line
–k
ln[A]₀

answer

for a first-order reaction, a plot of the natural log of the reactant concentration has a function of time yields a __ with a slope of __and a y-intercept of __

question

negative
positive

answer

for a first-order reaction, slope is __, but the rate constant is always __

question

1 / [A]_t = kt + 1 / [A]₀

answer

what is the second-order integrated rate law?

question

straight line
1 / [A]_t = kt + 1 / [A]_{0 -->}
y = mx + b

answer

The second-order integrated rate law is also in the form of an equation for a __

question

inverse
straight line
k
1 / [A]₀

answer

for a second-order reaction, plot the __ of the concentration of the reactant as a function of time, which yields a __ with a slope of __ and an intercept of __

question

[A]_t = -kt + [A]₀

answer

what is the zero-order integrated rate law?

question

straight line
[A]_t = -kt + [A]_{0 -->}
y = mx + b

answer

The zero-order integrated rate law is also in the form of an equation for a __

question

straight line
–k
[A]₀

answer

for a zero-order reaction, a plot of the concentration of the reactant as a function of time yields a __ with a slope of __ and an intercept of __

question

Half-life (t_1/2)

answer

__ of a reaction is the time required for the concentration of a reactant to fall to one-half of its initial value

question

rate constant
initial concentration

answer

The half-life expression defines the dependence of half-life on the __ and the __

question

different

answer

the half-life expression is __ for different reaction orders

question

t_1/2 = 0.693 / k

answer

what is the half-life of a first-order reaction?

question

independent

answer

For a first-order reaction, t_1/2 is __ of the initial concentration

question

constant

answer

Even though the concentration is changing as the reaction proceeds, the half-life (how long it takes for the concentration to halve) is __ for a first-order reaction half-life

question

first-order

answer

Constant half-life is unique to __ reactions

question

t_1/2 = 1 / k[A]₀

answer

what is the half-life of a second-order reaction?

question

initial concentration

answer

For a second-order reaction, the half-life depends on the __

question

decreases

answer

The half-life continues to get longer as the concentration __ for second-order reactions

question

t_1/2 = [A]₀ / k[A]₀

answer

what is the half-life or a zero-order reaction?

question

initial concentration

answer

For a zero-order reaction, the half-life depends on the __

question

reaction order
rate law

answer

The __ and __ must be determined experimentally

question

reactant(s)

answer

The rate law relates the rate of the reaction to the concentration of the __

question

reactant(s)
time

answer

The integrated rate law (which is mathematically derived from the rate law) relates the concentration of the __ to __

question

one-half of its initial value

answer

The half-life is the time it takes for the concentration of a reactant to fall to __

question

first-order

answer

The half-life of a __ reaction is independent of the initial concentration

question

zero-order
second-order

answer

The half-lives of __ and __ reactions depend on the initial concentration

question

C) the reaction is most likely second order because its rate depends on the concentration (therefore it cannot be zero order), and its half-life depends on the initial concentration (therefore is cannot be first order). For a second-order reaction, a doubling of the initial concentration results in the quadrupling of the rate

answer

A decomposition reaction, with a rate that is observed to slow down as the reaction proceeds, is found to have a half-life that depends on the initial concentration of the reactant. Which of the following is most likely to be true of this reaction?
A) a plot of the natural log of the concentration of the reactant as a function of time will be linear
B) the half-life of the reaction increases as the initial concentration increases
C) A doubling of the initial concentration of the reactants results in a quadrupling of the rate

question

temperature

answer

The rates of chemical reactions are highly sensitive to __

question

rate constant, k (which is actually a constant only when the temperature remains constant)

answer

The rate law for a reaction is Rate = k[A]ⁿ , the temperature dependence of the reaction rate is contained in the __

question

increase
faster

answer

Increase in temperature generally results in an __ in k, which results in a __ rate

question

Arrhenius equation

answer

__ – shows the relationship between the rate constant (k) and the temperature in kelvins (T)

question

Kelvins

answer

The Arrhenius equation has to have the temperature in __

question

k = Ae^{-Ea / RT}

answer

what is the Arrhenius equation?

question

A
-E_a
e^{-Ea / RT}
R

answer

in the Arrhenius equation,
__ = constant called the frequency factor (or pre-exponential factor)
__ = activation energy (or activation barrier)
__ = exponential factor
__ = gas constant

question

8.314 J / mol x K

answer

the gas constant (R) for the Arrhenius equation is what?

question

Activation energy (E_a)

answer

__ is an energy barrier or hump that must be surmounted for the reactants to be transformed into products

question

Frequency factor (A)

answer

__ is the number of times that the reactants approach the activation barrier per unit time

question

activated complex, or transition state

answer

To get from the reactant to the product, the molecule must go through a high-energy intermediate state called the __

question

initially weaken the chemical bonds

answer

The overall reaction is energetically downhill (exothermic), but it must first go uphill to reach the activated complex because energy is required to __

question

activation energy

answer

The energy required to reach the activated complex is the __

question

slower

answer

The higher the activation energy, the __ the reaction rate (at a given temperature)

question

approaches

answer

Frequency factor represents the number of __ to the activation barrier per unit time

question

not equivalent

answer

Approaching the activation barrier is __ to surmounting it

question

do not

answer

Most of the approaches to the activation barrier __ have enough total energy to make it over the activation barrier

question

Exponential factor

answer

__ is a number between 0 and 1 that represents the fraction of molecules that have enough energy to make it over the activation barrier on a given approach

question

successful
product

answer

Exponential factor is the fraction of approaches that are actually __ and result in the __

question

temperature (T)
activation energy (E_a)

answer

Exponential factor depends on both the __ and the __ of the reaction

question

one

answer

Low activation energy and a high temperature make the negative exponent small, so that the exponential factor approaches __

question

one (e^-0 = 1)
successful

answer

If the activation energy is zero, then the exponent is zero, and the exponential factor is exactly __. every approach to the activation barrier is __

question

negative number
very small

answer

A large activation energy and a low temperature make the exponent a very large __, so that the exponential factor become __

question

zero (e^-^infinitey = 0)

answer

As the temperature approaches 0 K, the exponent approaches an infinitely large number, and the exponential factor approaches __

question

increases

answer

As the temperature increases, the number of molecules having enough thermal energy to surmount the activation barrier __

question

distribution

answer

At any given temperature, a sample of molecules will have a __ of energies

question

small

answer

Commonly, only a __ fraction of molecules have enough energy to make it over the activation barrier

question

large

answer

A small change in temperature results in a __ difference in the number of molecules having enough energy to surmount the activation barrier

question

frequency factor

answer

The __ is the number of times that the reactants approach the activation barrier per unit time

question

exponential factor

answer

The __ is the fraction of approaches that are successful in surmounting the activation barrier and forming products

question

increases
decreases

answer

The exponential factor__ with increasing temperature, but __ with increasing activation energy

question

ln k = - E_a / R (1 / T) + ln A

answer

what is the equation for the Arrhenius plots?

question

straight line

answer

The Arrhenius plots equation is in the form of a __

question

Arrhenius plot

answer

A plot of the natural log of the rate constant (ln k) versus the inverse of the temperature in kelvins (1 / T) yields a straight line with a slope of –E_a / R and a y-intercept of ln A

question

kinetic

answer

Arrhenius plot used in the analysis of __ data

question

rate constant

answer

When either data are limited or plotting capabilities are absent, we can calculate the activation energy if we know the __ at just two different temperatures

question

ln (k₂ / k₁) = E_a / R (1 / T₁ – 1 / T₂)

answer

what is the two-point form of the Arrhenius equation?

question

two different

answer

the two-point form of the Arrhenius equation isused to calculate the activation energy from experimental measurements of the rate constant at __ temperatures

question

Collision model

answer

__ – a chemical reaction occurs after a sufficiently energetic collision between two reactant molecules

question

Collision theory

answer

__ – each approach to the activation barrier is a collision between the reactant molecules. So the value of the frequency factor should be the number of collisions that occur per second

question

smaller

answer

Frequency factors of most gas-phase chemical reactions tend to be __ than the number of collisions that occur per second

question

k = Ae^{-Ea / RT} = pze^{-Ea / RT}
p = orientation factor
z = collision frequency

answer

what two separate parts can the frequency factor be separated into?

question

collision frequency

answer

__ - number of collisions that occur per unit time, can be calculated for a gas-phase reaction from the pressure of the gases and the temperature of the reaction mixture

question

10⁹

answer

single molecule undergoes on the order of __ collisions every second (typical conditions)

question

sufficient energy

answer

for reaction to occur, molecules must collide with __

question

properly oriented

answer

not all collisions with sufficient energy will lead to products because the reactant molecules must also be __

question

break and form

answer

if two molecules are to react with each other, they must collide in such a way that allows the necessary bonds to __

question

small orientation factor

answer

__ = orientational requirements are very stringent – the molecules must be aligned in a very specific way for the reaction to occur

question

1

answer

reactions between individual atoms usually have orientation factors of approximately __, because atoms are spherically symmetric and thus any orientation can lead to the formation of products

question

don’t have to collide to react

answer

a few reactions have orientation factors greater than one, which means that reactants __

question

nuclei
weaken
form
products

answer

when two molecules with sufficient energy and the correct orientation collide the electrons on one of the atoms or molecules are attracted to the __ of the other; some bonds begin to __ while other bonds begin to __ and the reactants go through the transition state and are transformed into the __ --> how chemical reaction occurs

question

C) since the reactants in part A) are atoms, the orientation factors should be about one. The reactants in parts B) and C) are both molecules, so we expect orientation factors of less than one. Since the reactants in B) are symmetrical, we would not expect the collisions to have as specific an orientation requirement as in C), where the reactants are asymmetrical and must therefore collide in such way that a hydrogen atom is in close proximity to another hydrogen atom. Therefore, we expect C) to have the smallest orientation factor

answer

Which reaction would you expect to have the smallest orientation factor?
A) H(g) + I(g) --> HI(g)
B) H₂(g) + I₂(g) --> 2 HI (g)
C) HCl(g) + HCl(g) --> H₂(g) + Cl₂(g)

question

overall reaction

answer

In writing a chemical equation to represent a chemical reaction, we usually represent the __, not the series of individual steps by which the reaction occurs

question

Reaction mechanism

answer

__ – series of individual chemical steps by which an overall chemical reaction occurs

question

elementary step

answer

Each step in a reaction mechanism is an __

question

cannot

answer

Elementary step – step that __ be broken down into simpler steps, they occur as they are written (they represent the exact species that are colliding in the reaction)

question

equal

answer

For a reaction mechanism to be valid the individual steps in the mechanisms have to __ the overall reaction

question

Reaction intermediate

answer

__ – forms in one elementary step and is consumed in another

question

Reaction mechanism

answer

__ – complete, detailed description of the reaction at the molecular level – it specifies individual collisions and reactions that result in the overall reaction

question

measuring the kinetics of the overall reaction

answer

Can put a reaction mechanism together by __ and working backward to write a mechanism consistent with the measured kinetics

question

molecularity

answer

Elementary steps = characterized by their __ – number of reactant particles involved in the step

question

unimolecular
bimolecular

answer

Most common molecularities = __ and __

question

unimolecular

answer

A --> products = __

question

bimolecular

answer

A + A --> products = __

question

bimolecular

answer

A + B --> products = __

question

Termolecular

answer

__ = elementary steps in which three reactant particles collide; very rare because of low probability of three particles colliding simultaneously

question

balanced chemical equation

answer

Rate law for an elementary step can be deduced from the __ (rate law can’t be found for an overall chemical reaction with same method)

question

product

answer

Elementary step occurs though the collision of the reactant particles so the rate law is proportional to the __ of the concentrations of those particles

question

A + B --> products; Rate = k[A][B]

answer

rate for the bimolecular elementary step in which A reacts with B is proportional to the concentration of A multiplied by the concentration of B:

question

A + A --> products; Rate = k[A]²

answer

rate law for the bimolecular step in which A reacts with A is proportional to the square of the concentration of A:

question

1
k[A]

answer

A ---> products ; molecularity = __ ; Rate = __

question

2
k[A]²

answer

A+A --> products ; molecularity = __ ; Rate = __

question

2
k[A][B]

answer

A+B --> products ; molecularity = __ ; Rate = __

question

3
k[A]³

answer

A+A+A --> products; molecularity= __; Rate = __

question

3
k[A]²[B]

answer

A+A+B --> products; molecularity=__; Rate = __

question

3
k[A][B][C]

answer

A+B+C --> products; molecularity=__; Rate = __

question

overall order

answer

The molecularity of the elementary step is equal to the __ of the step

question

rate-determining step

answer

In most chemical reactions, one of the elementary steps – called the __ – is much slower than the others

question

limits
rate law

answer

Rate-determining step in a reaction mechanism __ the overall rate of the reaction and determines the __ for the overall reaction

question

1. The elementary steps in the mechanism must sum to the overall reaction
2. The rate law predicted by the mechanism must be consistent with the experimentally observed rate law

answer

what two conditions must be met for a reaction mechanism to be valid?

question

validated

answer

reaction mechanisms can only be __ not proven

question

is not

answer

valid mechanism __ a proven mechanism because other mechanisms may also fulfill both of the requirements; therefore, we can only say that a given mechanism is consistent with kinetic observations of the reaction and therefore possible

question

validity

answer

other types of data – such as the experimental evidence for a proposed intermediate – can further strengthen the __ of a proposed mechanism

question

overall reaction

answer

When proposed mechanism for a reaction has a slow initial step, the rate law predicted by the mechanism normally contains only reactants involved in the __

question

rate limiting step

answer

When a reaction mechanism begins with a fast initial step, some other subsequent step in the mechanism is the __.

question

reaction intermediates

answer

When a reaction mechanism begins with a fast initial step, the rate law predicted by the rate-limiting step may contain __

question

experimental rate law

answer

Reaction intermediates do not appear in the overall reaction equation, so a rate law containing intermediates cannot generally correspond to the __

question

concentrations of the reactants

answer

We can express the concentration of intermediates in terms of the __ of the overall reaction

question

limited

answer

In multistep mechanism where the first step is fast, the products of the first step can build up, because the rate at which they are consumed is __ by some slower step further along

question

re-form

answer

In mechanism with a fast first step the build up of products from the first step react with one another to __ the reactants

question

equilibrium

answer

In mechanism with a fast first step, as long as the first step is fast enough compared to the rate-limiting step, the first-step reaction will reach __

question

equals

answer

both the forward reaction and the reverse reaction occur. If equilibrium is reached, then the rate of the forward reaction __ the rate of the reverse reaction

question

concentration of the reactants
temperature

answer

Can speed up the rate of a reaction by increasing the __ or by increasing the __

question

catalyst

answer

Reaction rates can be increased by using a __ – substance that increases the rate of a chemical reaction but is not consumed by the reaction

question

alternative mechanism

answer

Catalyst provides an __ for the reaction – one in which the rate-determining step has a lower activation energy

question

homogeneous and heterogeneous

answer

catalysis can be categoriaed into what two types?

question

Homogeneous catalysis

answer

__ = the catalyst exists in the same phase (or state) as the reactants

question

Heterogeneous catalysis

answer

__ = the catalyst exits in a different phase than the reactants

question

heterogeneous catalysis

answer

Use of solid catalysts with gas-phase or solution-phase reactants is the most common type of __

question

alkenes

answer

Second example of heterogeneous catalysis involves the hydrogenation of double bonds with __

question

1. adsorption, 2. diffusion, 3. reaction, 4. desorption

answer

what are the four steps of a heterogeneous catalysis?

question

adsorption

answer

__ is the first step of a heterogeneous catalysis. the reactants are absorbed onto the metal surface

question

diffusion

answer

__ is the second step of a heterogeneous catalysis. the reactants diffuse on the surface until they approach each other

question

reaction

answer

__ is the third step of a heterogeneous catalysis. the reactants react to form the products

question

desorption

answer

__ is the fourth step of a heterogeneous catalysis. the products desorb from the surface into the gas phase

question

enzymes

answer

Living organisms rely on __, biological catalysts that increase rates of biochemical reactions

question

Enzymes

answer

__ – large protein molecules with complex 3-D structures. Within their structures there is a specific area called the active site

question

substrate

answer

properties and shape of the active site are just right to bind the reactant molecule, called the __

question

lowered
faster

answer

substrate fits into the active site perfectly, when substrate binds to the active site of the enzyme – through intermolecular forces – the activation energy of the reaction is greatly __, allowing the reaction to occur at a much __ rate

question

which
when

answer

enzymes give living organisms control over __reactions occur, and __ they occur

question

specific
efficient

answer

enzymes are extremely __ and __, speeding up reaction rates by factors of as much as a billion

question

catalyze

answer

if living organism wants to turn a particular reaction on, it produces or activates the correct enzyme to __ the reaction

question

kinetics

answer

Speed of a chemical reaction is determined by __

question

thermodynamics

answer

Extent of a chemical reaction is determined by __

question

large

answer

Reaction with a __ equilibrium constant proceeds nearly to completion – nearly all the reactants react to form products

question

small

answer

Reaction with a __ equilibrium constant barely proceeds at all – nearly all the reactants remain as reactants, hardly forming any products

question

extent

answer

Equilibrium constant is an experimentally measureable quantity and be used to predict and quantify the __ of a reaction

question

equilibrium constant, K

answer

The concentrations of the reactants and products in a reaction at equilibrium are described by the __

question

right
high
low

answer

Large value of K = reaction lies far to the __ at equilibrium = __ concentration of products and a __ concentration of reactants

question

left
high
low

answer

small value of K = reaction lies far to the __ at equilibrium = __ concentration of reactants and a __ concentration of products

question

how far a reaction proceeds

answer

value of K = measure of __

question

toward the products

answer

the larger the value of K, the more the reaction proceeds __

question

maintain equilibrium
counteract

answer

any system at equilibrium, responds to changes in ways that _; if any of the concentrations of the reactants or products change, the reaction shifts to __ that change

question

larger
product

answer

equilibrium for fetal hemoglobin is __ than the equilibrium constant for adult hemoglobin = the reaction tends to go farther in the direction of the __

question

increase
decrease

answer

Reaction rates generally __ with increasing concentration of the reactants (unless the reaction order is zero) and __ with decreasing concentration of the reactants

question

reversible

answer

A reaction that can proceed in both the forward and reverse directions is said to be __

question

equals

answer

Dynamic equilibrium for a chemical reaction is the condition in which the rate of the forward reaction __ the rate of the reverse reaction

question

occurring
occurring at the same rate

answer

In dynamic equilibrium, the forward and reverse reactions are still __; however, they are __

question

form at the same rate that they are depleted

answer

When dynamic equilibrium is reached, the concentrations of the reactants and products no longer change. They remain the same because the reactants and products __

question

equal to one another

answer

Because the concentrations of reactants and products no longer change at equilibrium does not mean that the concentrations of reactants and products are __ at equilibrium

question

most
small fraction

answer

Some reactions reach equilibrium only after __ of the reactants have formed products
Some reactions reach equilibrium when only a __ of the reactants have formed products

question

reaction

answer

When a reaction reaches equilibrium depends on the __

question

so small that it can be ignored

answer

Nearly all chemical reactions are at least theoretically reversible. In many cases, the reversibility is __

question

no longer change

answer

Equilibrium is reached in a chemical reaction when the concentrations of the reactants and products __

question

Dynamic equilibrium

answer

__: rate of forward reaction = rate of reverse reaction. Concentrations of reactant(s) and product(s) no longer change

question

slows down
speeds up

answer

As concentration of product increases, and concentrations of reactants decrease, rate of forward reaction __ and rate of reverse reaction __

question

constant

answer

When equilibrium is reached, both the forward and reverse reactions continue, but at equal rates, so the concentrations of the reactants and products remain __

question

concentrations

answer

When a chemical reaction reaches dynamic equilibrium the __ of reactants and products will not necessarily be equal at equilibrium

question

not equal
equal

answer

The concentrations of reactants and products are __ at equilibrium; rather, the rates of the forward and reverse reactions are __

question

quantify
concentrations

answer

The equilibrium constant is a way to __ the __ of the reactants and products at equilibrium

question

ratio
products
reactants

answer

The equilibrium constant (K) for the reaction is defined as the __ – at equilibrium – of the concentrations of the __ raised to their stoichiometric coefficients divided by the concentrations of the __ raised to their stoichiometric coefficients (Law of Mass Action)

question

K = [C]^c[D]^d / [A]^a[B]^b

answer

what is the expression for the equilibrium constant (K) also known as the Law of Mass Action?

question

molarity of products
molarity of reactants
molar concentration of A (M; molarity)

answer

in the equilibrium constant (K) equation (also known as the law of mass action) -->K = [C]^c[D]^d / [A]^a[B]^b
[C]^c[D]^d = __
[A]^a[B]^b = __
[A] = __

question

law of mass action

answer

the relationship between the balanced chemical equation and the expression of the equilibrium constant is known as the __

question

balanced chemical equation
law of mass action

answer

To express an equilibrium constant for a chemical reaction, examine the __ and apply the __

question

exponents

answer

The coefficients in the chemical equation become the __ in the expression of the equilibrium constant

question

larger

answer

A large equilibrium constant (K>>1) indicates that the numerator (which specifies the amounts of products at equilibrium) is __ than the denominator (which specifies the amounts of reactants at equilibrium).

question

forward

answer

when equilibrium constant is large (K>>1) the __ reaction is favored

question

far to the right
products
reactants

answer

When the equilibrium constant is large, the equilibrium point for the reaction lies __ – high concentration of __, low concentrations of __

question

long time

answer

A reaction with a large equilibrium constant may be kinetically very slow and take a __ to reach equilibrium

question

smaller

answer

A small equilibrium constant (K<<1) indicates that the numerator (which specifies the amounts of products at equilibrium) is __ than the denominator (which specifies the amounts of reactants at equilibrium)

question

reverse

answer

when the equilibrium constant is small (K<<1) the __ reaction is favored

question

far to the left
reactants
products

answer

When the equilibrium constant is very small, the equilibrium point for the reaction lies __ – high concentrations of __, low concentrations of __

question

K << 1

answer

__ = reverse reaction is favored; forward reaction does not proceed very far

question

K approximately equal to 1

answer

__ = neither direction is favored; forward reaction proceeds about halfway

question

K >> 1

answer

__ = forward reaction is favored; forward reaction proceeds essentially to completion

question

(b) the reaction mixture will contain 1 mol of A and 10 mol of B so that [B]/[A] = 10
...it will contain more moles of B when compared to A because the equilibrium constant (K) is 'large' so the forward reaction is favored and the concentration of products is large and the concentration of reactants is small

answer

The equilibrium constant for the reaction A (g) <--> B (g) is 10. A reaction mixture initially contains 11 mol of A and 0 mol of B in a fixed volume of 1 L. When equilibrium is reached, which statement is true?
(a) the reaction mixture will contain 10 mol of A and 1 mol of B
(b) the reaction mixture will contain 1 mol of A and 10 mol of B
(c) the reaction mixture will contain equal amounts of A and B

question

equilibrium constant

answer

If a chemical equation is modified in some way, then the __ for the equation must be changed to reflect the modification

question

1. reversing the equation
2. multiplying the coefficients in the equation by a factor
3. adding two or more individual chemical equations to obtain an overall equation

answer

what are the three common modifications for a chemical equation?

question

invert

answer

because the equilibrium constant must be changed if a chemical equation is modified in some way, if you reverse a chemical equation __ the equilibrium constant to reflect the modification of the chemical equation

question

same factor

answer

because the equilibrium constant must be changed if a chemical equation is modified in some way, if you multiply the coefficients in a chemical equation by a factor, raise the equilibrium constant to the __ to reflect the modification in the chemical equation

question

multiply the corresponding equilibrium constants

answer

because the equilibrium constant must be changed if a chemical equation is modified in some way, if you add two or more individual chemical equations to obtain an overall equation, __ by each other to obtain the overall equilibrium constant to reflect the modification in the chemical equation

question

concentration

answer

For gaseous reactions, the partial pressure of a particular gas is proportional to its __

question

equilibrium constant

answer

We can also express the __ in terms of partial pressures of the reactants and products

question

K_c

answer

__ = equilibrium constant with respect to the concentration in molarity

question

K_p

answer

__ = equilibrium constant with respect to partial pressures in atmospheres

question

partial pressure of each gas

answer

The expression for K_p takes the form of the expression for K_c, except that we use the __ in place of its concentration

question

P_A

answer

__ = partial pressure of gas A in units of atmospheres

question

not necessarily equal

answer

Since the partial pressure of a gas in atmospheres is not the same as its concentration in molarity, the value of K_p for a reaction is __ to the value of K_c

question

ideally

answer

As long as the gases are behaving __, we can derive a relationship between two constants (K_c and K_p)

question

number of moles of A (n_A) divided by its volume (V) in liters: [A] = n_A/V

answer

The concentration of an ideal gas A is the __

question

P_AV = n_ART --> P_A = (n_A/V)RT

answer

From the ideal gas law, we can relate the quantity n_A/V (concentration of an ideal gas 'A') to the partial pressure of A: __

question

P_A = [A]RT or [A] = P_A / RT

answer

[A] = n_A / V --> P_A = __ or [A] = __

question

K_p = K_c(RT)^c+d-(a+b)

answer

what is the equation for K_p (the equilibrium constant with respect to partial pressures)?

question

delta n

answer

__ = c + d – (a + b), which is the sum of the stoichiometric coefficients of the gaseous products minus the sum of the stoichiometric coefficients of the gaseous reactants

question

K_p = K_c(RT)^{delta n}

answer

K_p = __

question

0
equal

answer

If the total number of moles of gas is the same after the reaction as before, then delta n = __, and K_p is __ to K_c

question

corresponding units

answer

As long as concentration units are expressed in molarity for K_c and pressure units are expressed in atmospheres for K_p, we can skip the formality of units and enter the quantities directly into the equilibrium expression, dropping their __

question

reactants
products

answer

Many chemical reactions involve pure solids or pure liquids as __ or __

question

does not

answer

The concentration of a solid __ change because a solid does not expand to fill its container.

question

density

answer

A solids concentration depends only on its __, which is a constant as long as some solid is present

question

are not

answer

Pure solids – those reactants or products labeled in the chemical equation with an (s) – __ included in the equilibrium expression (because their constant value is incorporated into the value of K)

question

does not

answer

The concentration of a pure liquid __ change

question

excluded

answer

Pure liquids – reactants or products labeled in the chemical equation with an (l) – are also __ from the equilibrium expression

question

Heterogeneous

answer

__ equilibrium – the concentration of solid carbon (the number of atoms per unit volume) is constant as long as some solid carbon is present. The same is true for pure liquids. Thus, the concentrations of solids and pure liquids are not included in equilibrium constant expressions

question

(b) since delta n for gaseous reactants and products is zero, K_p equals K_c

answer

For which reaction does K_p = K_c
(a) 2Na₂O₂(s) + 2CO₂(g) « 2Na₂CO₃(s) + O₂(g)
(b) NiO(s) + CO(g) « Ni(s) + CO₂(g)
(c) NH₄NO₃(s) « N₂O(g) + 2H₂O(g)

question

concentrations of the reactants and products

answer

Most direct way to obtain an experimental value for the equilibrium constant of a reaction is to measure the __ in a reaction mixture at equilibrium

question

has no formal part in the calculation

answer

Since equilibrium constants depend on temperature, many equilibrium problems will state the temperature even though it __

question

moles per liter (M)
unitless

answer

The concentrations within K_c should always be written in __; however, the units are not normally included when expressing the value of the equilibrium constant, so K_c is __

question

equilibrium concentrations

answer

The __ of the reactants and products will depend on the initial concentrations (and in general vary from one set of initial concentrations to another)

question

same

answer

The equilibrium constant will always be the __ at a given temperature, regardless of the initial concentrations

question

the same

answer

Whether you start with only reactants or only products, the reaction reaches equilibrium concentrations in which the equilibrium constant is __

question

equilibrium constant, K

answer

No matter what the initial concentrations are, the reaction will always go in a direction so that the equilibrium concentrations – when substituted into the equilibrium expression – give the same __

question

the stoichiometry of the reaction

answer

We need only know the initial concentrations of the reactant(s) and the equilibrium concentration of any one reactant or product. The other equilibrium concentrations can be deduced from __

question

ICE table

answer

__ – table summarizing the initial conditions, the changes, and the equilibrium conditions;

question

I = initial, C = change, E = equilibrium

answer

for the ICE table, I = __, C = __, E = __

question

equilibrium concentrations
ICE table

answer

to calculate the equilibrium constant, we can use the balanced equation to write an expression for the equilibrium constant and the substitute the __ from the __

question

right (toward the products)

answer

When the reactants of a chemical reaction mix, they generally react to form products – we say that the reaction proceeds to the __

question

magnitude of the equilibrium constant

answer

The amount of products formed when equilibrium is reached depends on the __

question

reaction quotient

answer

In order to compare the progress of a reaction to the equilibrium state of the reaction, we use a quantity called the __

question

any point in the reaction

answer

Reaction quotient (Q_c) – the ratio – at __ – of the concentrations of the products raised to their stoichiometric coefficients divided by the concentrations of the reactants raised to their stoichiometric coefficients

question

Q_p

answer

For gases with amounts measured in atmospheres, the reaction quotient uses the partial pressures in place of concentrations and is called __

question

equilibrium constant
reactant quotient

answer

The difference between the reaction quotient and the equilibrium constant is that, at a given temperature, the __ has only one value and it specifies the relative amounts of reactants and products at equilibrium
The __ depends on the current state of the reaction and has many different values as the reaction proceeds

question

zero (Q_c = 0)

answer

In a reaction mixture containing only reactants, the reaction quotient is __

question

infinite (Q_c = infinitey)

answer

In a reaction mixture containing only products, the reaction quotient is __

question

one (Q_c = 1)

answer

In a reaction mixture containing both reactants and products, each at a concentration of 1M, the reaction quotient is __

question

reaction toward equilibrium

answer

The reaction quotient is useful because the value of Q relative to K is a measure of the progress of the __

question

equal

answer

At equilibrium, the reaction quotient is __ to the equilibrium constant

question

less than

answer

If Q is__ K, Q must therefore get larger as the reaction proceeds toward equilibrium. Q becomes larger as the reactant concentration decreases and the product concentration increases – the reaction proceeds to the right

question

greater than

answer

If Q is __ K, Q must therefore get smaller as the reaction proceeds toward equilibrium. Q gets smaller as the reactant concentration increases and the product concentration decreases – the reaction proceeds to the left

question

equal to

answer

If Q is __ K the reaction is at equilibrium – the reaction will not proceed in either direction

question

progress of a reaction

answer

The reaction quotient (Q) is a measure of the __ toward equilibrium

question

goes to the right (toward products)
goes to the left (toward reactants)
is at equilibrium

answer

Q < K ; reaction __
Q > K ; reaction __
Q = K ; reaction __

question

reactant or product

answer

Calculating equilibrium concentrations of reactants or products from the equilibrium constant allow us to calculate the amount of a __ at equilibrium

question

(1) finding equilibrium concentrations when we know the equilibrium constant and all but one of the equilibrium concentrations of the reactants and products; and (2) finding equilibrium concentrations when we know the equilibrium constant and only initial

answer

Calculating equilibrium concentrations of reactants or products from the equilibrium constant can be divided into what two categories?

question

1. Using the balanced equation as a guide, prepare a table showing the known initial concentrations of the reactants and products (ICE table)
2. Use the initial concentrations to calculate the reaction quotient (Q) for the initial concentrations. Compare Q to K to predict the direction in which the reaction will proceed.
3. Represent the change in the concentration of one of the reactants or products with the variable x. Define the changes in the concentrations of the other reactants or products in terms of x
4. Sum each column for each reactant and product to determine the equilibrium concentrations in terms of the initial concentrations and the variable x
5. Substitute the expressions for the equilibrium concentrations (from step 4) into the expression for the equilibrium constant. Using the given value of the equilibrium constant, solve the expression for the variable x.
6. Substitute x into the expressions for the equilibrium concentrations of the reactants and products (from step 4) and calculate the concentrations
7. Check your answer by substituting the computed equilibrium values into the equilibrium expression. The calculated value of K should match the given value of K

answer

what is the procedure for finding equilibrium concentrations from initial concentrations and the equilibrium constant?

question

1. Using the balanced equation as a guide, prepare a table showing the known initial partial pressures of the reactants and products
2. Use the initial partial pressures to calculate the reaction quotient (Q). compare Q to K to predict the direction in which the reaction will proceed
3. Represent the change in the partial pressure of one of the reactants or products with the variable x. Define the changes in the partial pressures of the other reactants or products in terms of x
4. Sum each column for each reactant and product to determine the equilibrium partial pressures in terms of the initial partial pressures and the variable x
5. Substitute the expressions for the partial pressures (from step 4) into the expression for the equilibrium constant. Use the given value of the equilibrium constant to solve the expression for the variable x
6. Substitute x into the expressions for the equilibrium partial pressures of the reactants and products (from step 4) and calculate the partial pressures
7. Check your answer by substituting the calculated equilibrium partial pressures into the equilibrium expression. The calculate value of K should match the given value of K

answer

what is the procedure for finding equilibrium partial pressures when you are given the equilibrium constant and initial partial pressures?

question

1. Using the balanced equation as a guide, prepare a table showing the known initial concentrations of the reactants and products
2. Use the initial concentrations to calculate the reaction quotient (Q). Compare Q to K to predict the direction that the reaction will proceed
3. Represent the change in the concentration of one of the reactants or products with the variable x. Define the changes in the concentrations of the other reactants or products with respect to x
4. Sum each column for each reactant and product to determine the equilibrium concentrations in terms of the initial concentrations and the variable x
5. Substitute the expressions for the equilibrium concentrations (from step 4) into the expression for the equilibrium constant. Use the given value of the equilibrium constant to solve the expression for the variable x.

in this case, the resulting equation is cubic in x. Although cubic equations can be solved, the solutions are not usually simple. However, since the equilibrium constant is small, we know that the reaction does not proceed very far to the right. Therefore, x will be a small number and can be dropped from any quantities in which it is added to or subtracted from another number (as long as the number itself is not too small)

check whether your approximation was valid by comparing the calculated value of x to the number it was added to or subtracted from. The ratio of the two numbers should be less than 0.05 ( or 5%) for the approximation to be valid. If approximation is not valid proceed to step 5a

5a. if the approximation is not valid, you can either solve the equation exactly (by hand or with your calculator), or use the method of successive approximations. In this case, we use the method of successive approximations

substitute the value obtained for x in step 5 back into the original cubic equation, but only at the exact spot where x was assumed to be negligible and then solve the equation for x again. Continue this procedure until the value of x obtained from solving the equation is the same as the one that is substituted into the equation

6. Substitute x into the expressions for the equilibrium concentrations of the reactants and products (from step 4) and calculate the concentrations
7. Check your answer by substituting the calculated equilibrium values into the equilibrium expression. The calculated value of K should match the given value of K. Note that the approximation method and rounding errors could cause a difference of up to about 5% when comparing values of the equilibrium constant

answer

what is the procedure for finding equilibrium concentrations from initial concentrations in cases with a small equilibrium constant?

question

(a) the x is small approximation is most likely to apply to a reaction with a small equilibrium constant and an initial concentration of reactant that is not too small. The bigger the equilibrium constant and the smaller the initial concentration of reactant, the less likely that the x is small approximation will apply

answer

For the generic reaction, A(g) « B(g), consider each value of K and initial concentration of A. For which set will the x is small approximation most likely apply?
(a) K = 1.0 x 10^-5; [A] = 0.250M
(b) K = 1.0 x 10^-2; [A] = 0.250M
(c) K = 1.0 x 10^-5; [A] = 0.00250M
(d) K = 1.0 x 10^-2; [A] = 0.00250M

question

minimize the disturbance

answer

Le Chatelier’s principle states that the chemical system will respond to __ when a chemical system already at equilibrium is disturbed

question

Le Chatelier’s principle

answer

__: when a chemical system at equilibrium is disturbed, the system shifts in a direction that minimizes the disturbance

question

changing the concentration of a reactant or product, changing the volume or pressure, and changing the temperature

answer

how can we distrub a system in chemical equilibrium?

question

<
right (in the direction of the products)

answer

If a chemical system is at equilibrium, increasing the concentration of one or more of the reactants (which makes Q __ K) causes the reaction to shift to the __

question

>
left (in the direction of the reactants)

answer

If a chemical system is at equilibrium increasing the concentration of one or more of the products (which makes Q __ K) causes the reaction to shift to the __

question

>
left (in the direction of the reactants)

answer

If a chemical system is at equilibrium decreasing the concentration of one or more of the reactants (which makes Q __ K) causes the reaction to shift to the __

question

<
right (in the direction of the products)

answer

If a chemical system is at equilibrium decreasing the concentration of one or more of the products (which makes Q __ K) causes the reaction to shift to the __

question

pressure

answer

Changing the volume of a gas (or a gas mixture) results in a change in __

question

inversely
increase
decrease

answer

Pressure and volume are __ related: a decrease in volume causes an __ in pressure, and an increase in volume causes a __ in pressure

question

minimize that change

answer

If the volume of a reaction mixture at chemical equilibrium is changed, the pressure changes and the system will shift in a direction to __

question

lower

answer

From the ideal gas law (PV = nRT), we know that lowering the number of moles of a gas (n) results in a __ pressure (P)

question

higher

answer

From the ideal gas law (PV = nRT), we know that increasing the number of moles of gas (n) results in a __ pressure (P)

question

increases
do not change
no
does not shift in either direction

answer

If we keep the volume the same, but increase the pressure by adding an inert gas to the mixture, the overall pressure of the mixture __, but the partial pressures of the reactants and products __. There is __ effect and the reaction __

question

has the fewer moles of gas particles

answer

If a chemical system is at equilibrium decreasing the volume causes the reaction to shift in the direction that __

question

greater number of moles of gas particles

answer

If a chemical system is at equilibrium increasing the volume causes the reaction to shift in the direction that has the __

question

produces no effect on the equilibrium

answer

If a chemical system is at equilibrium, if a reaction has an equal number of moles of gas on both sides of the chemical equation, then a change in volume __

question

no effect on the equilibrium

answer

If a chemical system is at equilibrium, adding an inert gas to the mixture at a fixed volume has __

question

temperature

answer

In considering the effect of a change in volume, we are assuming that the change in volume is carried out at a constant __

question

pressure

answer

In considering the effect of a change in temperature, we are assuming that the heat is added (or removed) at constant __

question

counter that change

answer

If the temperature of a system at equilibrium is changed, the system will shift in a direction to __

question

product in an exothermic reaction

answer

An exothermic reaction (negative delta H) emits heat and we can think of heat as a __

question

reactant in an endothermic reaction

answer

An endothermic reaction (positive delta H) absorbs heat and we can think of heat as a __

question

shift left
reactants
products
smaller

answer

At constant pressure, raising the temperature of an exothermic reaction (think of this as adding heat) is similar to adding more product, causing the reaction to __. The new equilibrium mixture will have more __ and fewer __ and therefore a __ value of K

question

equilibrium constant

answer

Changing the temperature does change the value of the __

question

exothermic

answer

At constant pressure, lowering the temperature of an __reaction, causes the reaction to shift right, releasing heat and producing more products because the value of K has increased.

question

shift right
products
increased

answer

For an endothermic reaction at constant pressure, raising the temperature (adding heat) causes the reaction to __ to absorb the added heat and producing more __ because the value of K has __

question

shift left
products
lowering

answer

For an endothermic reaction at constant pressure, lowering the temperature (removing heat) of a reaction mixture causes the reaction to __, releasing heat, forming less __, and __ the value of K

question

Increasing

answer

In an exothermic chemical reaction, heat is a product. __ the temperature causes an exothermic reaction to shift left (in the direction of the reactants); the value of the equilibrium constant decreases

question

Decreasing

answer

In an exothermic chemical reaction, heat is a product. __ the temperature causes an exothermic reaction to shift right (in the direction of the products); the value of the equilibrium constant increases

question

Increasing

answer

In an endothermic chemical reaction, heat is a reactant. __ the temperature causes an endothermic reaction to shift right (in the direction of the products); the equilibrium constant increases

question

Decreasing

answer

In an endothermic chemical reaction, heat is a reactant. __ the temperature causes an endothermic reaction to shift left (in the direction of the reactants); the equilibrium constant decreases

question

endothermic direction

answer

Adding heat favors the __

question

exothermic direction

answer

Removing heat favors the __

question

metastable

answer

Systems that are not in
thermodynamic equilibrium
but are kinetically stable are
called __.

question

concentration, pressure, temperature

answer

for a system at equilibrium, the principle can be used to qualitatively predict the effects of changes in what

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