Regents Chemistry

question

 

What is the same in an isotope and what is different in an isotope?

 

answer

 

Same Protons

 

 

Different Neutrons

question

What is the nuclear charge of fluorine?

answer

 

+ 9

 

question

State two major findings about the atom.

answer

The atom is mostly empty space.

The nucleus is small and positive.

question

Explain how spectral lines are produced, in terms of electrons.
answer

 

Electrons fall from the excited to the ground state.

 

question

In a nuclear reaction mass is always “lost”. Explain this loss of mass.

answer

Mass was converted to energy.

question

 

Calculate the average atomic mass of carbon:

 

98% 12C and 2% 14C

 

answer

 

 (98/100) (12) + (2/100) (14) = 12.04

 

question

Why would two elements have similar chemical properties?
answer

Same group.

Same Valence electrons.

question

Why does the radius increase as you move down a group?
answer

 

More Shells

 

question

Describe three properties of metals
answer

 

good conductor

malleable and ductile

 shiny

question

Describe three properties of nonmetals
answer

 

poor conductor

brittle

dull

question

Which elements lose electrons when forming ions?

What happens to the radius?

answer

metals

decreases

question

 

 

Which elements gain electrons when forming ions?

What happens to the radius?

answer

 

nonmetals

increases

question

Name the four types of chemical reactions.
answer

 

synthesis

decomposition

single replacement

double replacement

question

[image]
answer

Kinetic Energy Increases

Potential Energy remains the same

question

[image]
answer

Kinetic Energy remains the same

Potential Energy Increases

question

 

How is an ionic bond formed, in terms of electrons?

answer

 

Electrons are transferred.

question

 

How is a covalent bond formed, in terms of electrons?

answer

 

Electrons are shared.

question

 

What makes a bond more polar, in terms of electronegativity?

answer

 

Greater difference in electronegativity.

question

 

What makes a covalent bond polar?

answer

 

Unequal sharing of electrons.

question

 

What makes a covalent bond nonpolar?

answer

 

Equal sharing of electrons.

question

 

Why is a molecule polar?

(HINT:SNAP)

answer

 

Asymmetrical.

question

 

Why is a molecule nonpolar?

(HINT:SNAP)

answer

 

Symmetrical.

question

 

Properties of ionic solids.

answer

 

High Melting Point

Strong forces

Conductor only in the liquid phase

question

 

Properties of molecular solids(covalent bonds).

answer

 

Low Melting Point

 Weak forces

Poor Conductor

question

 

Properties of metallic solids.

answer

 

High Melting Point

Strong forces

Great Conductor

question

 

What makes a good conductor(in terms of particles)?

answer

 

Mobile Particles.

question

 

How do you increase the solubility of a solid in a liquid?

answer

 

Raise temperature

question

 

How do you increase the solubility of a gas in a liquid?

answer

 

Lower temperature

Increase pressure

question

 

State, in terms of molecular polarity, why 1,2-ethanediol is soluble in water.

answer

 

It is polar like water

“LIKE DISSOLVES LIKE”

question

 

When is a gas most ideal?

answer

 

High Temperature & Low Pressure

question

 

What happens to the freezing and boiling point when salt is added to water?

answer

 

F.P. decreases

B.P. increases

question

 

What is entropy?

What phase has the most entropy?

answer

 

Disorder of a system.

gas

question

 

How do you increase the rate of a reaction?

answer

 

 Increase temperature

 Increase concentration

 Increase surface Area

Increase pressure(gas)

Add a catalyst

question

 

Why does increasing the temperature increase the rate of a reaction, in terms of the collision theory?

answer

 

There are more collisions.

question

 

How does a catalyst increase the rate of a reaction?

answer

 

Lowers the activation energy.

question

 

What occurs at equilibrium?

answer

 

Rates are EQUAL

Concentrations are constant.

question

 

What type of positive ions do acids produce in water?

answer

 

Acids: Hydrogen(H+) or hydronium.(H3O+)

question

 

What type of negative ions do bases produce in water?

answer

 

Bases: Hydroxide (OH)

question

 

What is a neutralization reaction?

answer

 

Acid + Base à Salt + Water

question

 

What is an electrolyte?

Name three substances that are electrolytes.

answer

 

Substance that conducts electricity in water.

-Acid, Base, Ionic

question

 

What occurs during oxidation?

answer

 

Lose electrons (LEO)

Oxidation number increases

question

 

What occurs during reduction?

answer

 

Gain electrons (GER)

Oxidation number decreases

 

question

 

What is an endothermic reaction?

Draw a potential energy diagram for this reaction.

 

answer

[image]
question

 

What is an exothermic reaction?

Draw a potential energy diagram for this reaction

answer

[image]
question

 

What is the difference between a voltaic and an electrolytic cell?

answer

 

Voltaic is spontaneous and converts chemical to electrical energy

 

Electrolytic is non-spontaneous and converts electrical to chemical energy.

 

question

 

What is the purpose of a salt bridge?

answer

 

Allow the flow of ions.

question

 

What is the difference between a saturated and unsaturated hydrocarbon in terms of bonding?

answer

 

Saturated- all single bonds between C’s.

Unsaturated- double or triple bond between two C’s.

question

 

What is an isomer?

answer

 

Same Molecular formula, but different structural formula.

question

 

Identify the type of organic reaction shown.

(a.)  Br2 + CH4 → CH3Br + HBr

(b.) C4H8 + Cl2 → C4H8Cl2

 

answer

 

(a.) Substitution

     (b. )Addition

 

question

 

2SO2(g) + O2(g)ßà 2SO3(g) + energy

Explain, in terms of LeChatelier’s principle, why the concentration of SO2(g) increases when the temperature is increased.

 

answer

 

Shifts left.

question

 

a. Explain, in terms of attraction, why a substance has a low boiling point.

 

b. Explain, in terms of attraction, why a substance has a high  boiling point.

answer

 

a. Weak forces.

b. Strong forces

question

[image]
answer

 

A- Reactants

B- Heat of Reaction

C- Products

D- Activation Energy

Get instant access to
all materials

Become a Member