Chap 6-9 – Chemistry – Flashcards
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Unlock answers| Define Physical Change |
The identity and composition of the substance do not change. The state can change, or the material can be torn into smaller pieces. |
| Define Chemical Change |
Reacting substances form new substances with different compositions and properties. A chemical reaction takes place. |
Balance:
CH4 + O2 -----> CO2 + H2O |
| CH4 + 2O2 -----> CO2 + 2H2O |
Define Combination reaction
|
two or more elements bond to form one product
A + B-------> AB |
| define Decompostition Reaction |
A reactant splits into two or more simpler products.
AB -----> A + B |
| Define Single Replacement Reaction |
A reacting element switches place with an element in the other reacting compound
A + BC ----> AC + B |
| Define Double Replacement Reaction |
the positive ions in the reacting compounds switch places
AB + CD ------> AD + CB |
| Define Oxidation |
| Loss of electrons |
| Define Reduction |
| the gain of electrons |
| Oxidation always involves: |
Loss of electrons Electrons are a product
May Involve: addition of oxygen, loss of hydrogen |
| Reduction always involves: |
Gain of electrons electrons are a reactant
May involve: Loss of oxygen, Gain of hydrogen |
| # of particles in a mole? |
| 6.02x10^23 |
| Define Molar mass |
the mass of one mole of a substance the atomic mass of an element expressed in grams |
n the reaction or iron and sulfur, how many moles of sulfur are needed to react with 6.0 moles of iron?
2Fe + 3S -----> Fe2S3 |
6.0moles Fe x 3 moles S __________ 2 moles Fe
= 9.0 Moles of S |
Mass of product from mass of reactant
pg 238
Sample prob. 6.11 |
| Percent Yield equation |
actual yield ____________ x 100 Theoretical yield |
| define endothermic reaction |
| the energy of the products is greater than that of the reactants |
| Define exothermic |
| the products have less energy than the reactants. |
| define mole |
| unit that contains 6.02x10^23 items |
| Define coefficient |
| whole numbers in front of formulas to balance an equation |
| define oxidizing agent |
Oxidizing agents give oxygen to another substance or remove hydrogen from it. oxidizing agent is reduced |
| Define reducing agent |
Reducing agents remove oxygen from another substance or give hydrogen to it.
reducing agent is oxidized. |
| Major features of the kinetic theory of gases? |
1- A gas consists of small particles that move randomly with rapid velocities 2- the attractive forces between the particles of a gas can be neglected 3- the actual volume occupied by gas molecules is extremely small compared to the volume that the gas occupies 4- Gas particles are in constant motion, moving rapidly in straight paths 5-the average kinetic energy of gas molecules is proportional to the kelvin temperature. |
Boyle's Law? (equation) ; |
| P1V2 = P2V2 |
| Charles Law? (equation) |
V1 ; ; = ; ; ;V2 _____ ; ;_______ T1 ; ; ; ; ; ; ;T2 |
| Gay-Lussac's Law? (equation) |
P1 = P2 _____ _______ T1 T2 |
| The combined Gas Law? (equation) |
P1V1 = P2V2 _______ ________ T1 T2 |
| Avogadro's Law? (equation) |
V1 ; = ; V2 ______ ; ;______ N1 ; ; ; ; ;N2 |
| The ideal Gas Law? (equation) |
| PV = nRT |
| What is R (ideal gas constant) |
| R (ALWAYS) = 0.0821 L |
| What is Standard Temperature? (STP) |
| 0 degree C (273K) |
| What is Standard Pressure? (STP) |
| 1 atm (760 mmHg) |
| Define atmospheres and millimeters (atm) |
| the most common units used for gas measurement |
| Relate temperature and pressure to gas |
As temperature increases the pressure of a gas increases ; As temperature decreases the pressure of a gas decreases; |
| relate vapor pressure to atmospheric pressure and boiling point |
A liquid reaches its boiling point when its vapor pressure becomes equal to the external pressure. ; ex: at an atm of 760mmHg, water will boil at 100C, the temperature at which its vapor pressure reaches 760mmHg. |
| Describe the relationship between the amount of a gas and its volume |
| (avagadro's law) if the number of moles of a gas is doubled, then the volume will double as long as we do not change the pressure or temperature. |
| Volume of 1 mole of gas at STP? |
1 mole of gas = 22.4 L
22.4 L is considered a gas's molar volume |
| Describe how the partial pressure of oxygen gas vary in the lungs, blood, and tissues, and how those levels serve to deliver oxygen from the air to the tissues.; |
| partial pressure of oxygen in venous blood is 40 mmHg, oxygen diffuses from the aveoli into the bloodstream. The oxygen combines with hemoglobin, which carries it to the tissues of the body, where the partial pressure of oxygen can be very low. Oxygen diffuses from the blood where the partial pressure of oxygen is high into the tissues where oxygen pressure is low. (carbon dioxide diffuses from the tissues into the bloodstream and is carried to the lungs) |
| Daltons Law? (equation) |
P total= p1 + p2 + p3 + ...... ; total pressure= sum of the partial pressures |
| Define Barometer |
| measures atmospheric pressure |
| Define pressure gradient |
| the rate of decrease (that is, the gradient) of pressure in space at a fixed time |
| Define solute and solvent |
| a solution is a homogeneous mixture in which one substance called the solute is uniformly dispersed in another substance called the solvent. |
| Describe strong electrolytes |
100% of the solute dissociates into ions. Ex: Sodium Chloride (NaCl) ; when the electrodes from the light bulb apparatus are placed in the NaCl solution, the light bulb is very bright. |
| Define weak electrolytes |
only a small percentage of the dissolved solute dissociates into ions.; Ex: HF ; When the electrodes are placed in a solution of a weak electrolyte, the glow of the light bulb is very dim.; |
| Define Nonelectrolytes |
a nonelectrolyte such as sucrose (sugar) dissolves in water as molecules which do not dissociate into ions.; ; When electrodes are placed in a solution of a nonelectrolyte, the light bulb does not glow because the solution does not conduct electricity; |
| Define colloids |
| the particles in a colloidal dispersion are much larger than solute particles in a solution. |
| Define suspensions |
| heterogeneous, nonuniform mixtures that are very different from solutions or colloids. So large, can often be seen with the naked eye. - trapped by filters and semipermeable membranes |
| Define Solutions |
Are homogeneous mixtures of two or more substances Consist of a solvent and one or more solutes. |
| Describe hydrogen boding and water |
Water Is a polar molecule. Forms hydrogen bonds between the hydrogen atom in one molecule and the oxygen atom in a different water molecule |
| Describe the effect of temperature on solubility |
Of most solids increases as temperature increases. Of gases decreases as temperature increases. |
| Define percent concentration (equation) |
Is the amount of solute dissolved in a specific amount of solution. amount of solute amount of solution
|
| If finding percent concentration, you already have percent, and you need grams. What do you do? |
Molarity question! change mL ---> L and then multiply moles/1 L
Once you have the moles, multiply by the molar mass to get answer. |
| Equation for mass/volume percent? |
grams of solute ______________ x100 milliliters of solution |
| Equation for dilution |
| C1V1 = C2V2 |
| How many mL are in a L? |
| 1000mL = 1L |
| Define osmosis |
| water molecules move through a semipermeable membrane from the solution with the lower concentration of solute into a solution with the higher solute concentration. |
| Define dialysis |
| A semipermeable membrane, called a dialyzing membrane, permits small solute molecules and ions as well as solvent water molecules to pass through, but it remains large particles, such as colloids. |
| What happens to a red blood cell in hypotonic solutions? |
| water flows into the red blood cell causing it to swell and burst. |
| What happens to a red blood cell in isotonic solutions? |
exert the same osmotic pressure as body fluids.
"equal to"
red blood cell retains its normal volume |
| What happens to a red blood cel in hypertonic solutions? |
| water leaves the red blood cell causing it to SHRINK |
| What is the molarity of 60.0g of NaOH in 0.250L of solution? (pg. 316) |
60.0g NaOH x 1 mole _________ 40.0g NaOH
= 1.50 moles
1.50 moles NaOH ___________________ 0.250 L
= 6.00 M NaOH |
| How many Liters of a 2.00 M NaCl solution are needed to provide 67.3g of NaCl? (pg. 317) |
67.3g NaCl x 1 mole NaCl x 1L NaCl __________ __________ 58.5g NaCl 2.00moles NaCl
=0.575 L of NaCl solution |
| Define isotonic |
exert the same osmotic pressure as body fluids "equal to" |
| Define Hypertonic |
| higher solute concentration water leaves the cell by osmosis. |
| Define Crenation |
| As water is lost the cell shrinks. |
| Define Hypotonic |
when a red blood cell is placed in pure water, water flows into the cell by osmosis. "lower than" |
| define Hemolysis |
| increase in fluid causes the cell to swell, and possibly burst |
| Define osmolarity |
| the measure of solute concentration |
| Define hydration |
| when ions form a solution they undergo hyrdration as water molecules surround each ion. |
| Define saturated |
the rate of the reaction that dissolves the solute becomes equal to the rate of recrystallization.
|
| Define collision theory |
| indicates that a reaction takes place only when molecules collide with the proper orientation and with sufficient energy. |
| Identify the factors that will speed up or slow down a reaction. |
Temperature: at higher temperatures the increase in kinetic energy makes the reacting molecules move faster. Concentrations of reactions: the rate of the reaction increases when the concentrations of the reactants increase. Catalysts: another way to speed up a reaction is to lower the activation energy. when activation energy is lowered more collisions provide sufficient energy for reactants to form product. |
| Define activation energy |
| the amount of energy required to break the bonds between atoms of reactants |
| Define rate of reaction |
determined by measuring the amount of a reactant used up, or the amount of a product formed, in a certain period of time:
change in concentration ______________________ change in time |
| Define catalysts |
| speeds up reaction by providing a different way for the reaction to proceed that has a lower activation energy. |
| Define forward reactions |
all of the reactants were converted to products.
-----> |
| Define reverse reactions |
products come together to form the reactants
-----> <------ |
| At equilibrium..... |
| the rate of the forward reaction is equal to the rate of the reverse reaction. |
| write equilibrium constant exoression |
products _________ Reactants
=
[c]^c [D]^d ______________ [A]^a [B]^b |
| Define heterogeneous equilibrium |
| when the reactants and products are in two or more physical states |
| Define homogeneous equilibrium |
| a reaction in which all the reactants and products are in the same physical state |
| If products are LARGE then what will Kc be? |
[PRODUCTS] ______________ = LARGE Kc [reactants] |
| When the reactants are large then what will Kc be? |
[products] __________ = small Kc [REACTANTS] |
