Chem 2 ACS final exam

ideal gas law conditions

low pressure, high temperature

boyle's law

p1v1=p2v2

gases are highly _________

compressible

gases expand ________ to fill the container they are placed in

spontaneously

the distance between molecules in gases are _____

far apart in gases

1 mol of any gas at STP is

22.4 liters

the lighter the gas, _____

the faster the effusion rate

the deviation from ideal behavior of a gas is most evident at high _____ and low _____

pressure, temp

Non reacting gas mixtures are homongeneous

normal melting point at

760 torr or 1 atm

the kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because_______

both the gas molecules collide more frequently with the wall and the gas molecules collide more energetically with the wall

hydrogen bonding

H with N,O,F

isothermal means

at constant temperature

STP

273.15 K and 1 atm

the van der Waals equation

gas particles have non-zero volumes and interact with each other, molar volumes of gases of different types are different, the non-zero volumes of gas particles effectively decrease the amount of "empty" space between them, the molecular attractions between particles of gas decreases the pressure exerted by the gas

viscosity is __

the resistance to flow

viscosity increases as

temperature decreases, molecular weight increases, intermolecular forces increase

a volatile liquid is one that

readily evaporates

the vapor pressure of any substance at its normal boiling point is

1 atm

as intermolecular forces increase, vapor pressure ___

decreases

as intermolecular forces increase, normal boiling point ___

increases

as intermolecular forces increase, heat of vaporization ___

increases

as intermolecular forces increase, surface tension ___

increases

how are boiling points affected by intermolecular forces?

stronger intermolecular forces between molecules make it more difficult for those molecules to be pulled apart. Therefore, stronger intermolecular forces result in higher boiling points

solid to liquid

liquid to solid

melting

freezing

liquid to gas

gas to liquid

evaporation

condensation

solid to gas

gas to solid

sublimation

depostition

low vapor pressure

higher surface tension

higher vapor pressure

lower boiling point

large intermolecular forces in a substance are manifested by

low vapor pressure, high boiling points, high heats of fusion, high critical temperatures and pressures

the stronger the forces between the particles,

the higher the melting point

the higher the boiling point

the lower the vapor pressure

the higher the viscosity

the greater the surface tension

an unsaturated solution is one that

has a concentration lower than the solubility

a solution with a concentration higher than the solubility is

supersaturated

molarity varies with

temperature

a saturated solution

contains dissolved solute in equilibrium with undissolved solute

which of the following substances is more likely to dissolve in CH3OH?

the one with hydrogen bonding

which of the following substances is more likely to dissolve in CCl4

the one with London dispersion bonding

what are the five principle factors that influence the rate of chemical change

1. chemical nature

2. ability of the reactants to come in contact with each other

3. concentration of reactants

4. temperature

5. availability of rate-acceleration agents called catalysts

for a given reaction, adding a catalyst increases the rate of reaction by

providing an alternate reaction pathway that has a lower activation energy

doubling the concentration of the 1st order

doubling the concentration of the 2nd order

doubles the rate

quadruple the rate

lightest gas will have

lowest partial pressure

the rate of reaction depends on ________ but the rate constant does not

concentration

for a reaction that is first order with respect to reactant A, and third-order overall

rate=k(A)(B)2

the rate determining step is

the slowest step

the mechanism is

produced in one step and consumed in the other and won't be final product

the difference between the energy of the starting molecule and the highest energy along the reaction pathway is known as the

activation energy

when the direction of an equation is reversed

the new equilibrium constant is the reciprocal of the original

when the coefficients in an equation are multiplied by a factor

the equilibrium constant is raised to the power equal to that factor

The equilibrium law for a heterogeneous reaction is written without concentration terms for

pure solids or pure liquids

When K is very large:

The reaction proceeds far toward completion. The position of equilibrium lies far to the right, toward the products.

When K ≈ 1:

The concentrations of reactants and products are nearly the same at equilibrium. The position of equilibrium lies approximately midway between the reactants and products.

When K is very small:

Extremely small amounts of products are formed. The position of equilibrium lies far to the left, toward the reactants.

at equilibrium

the rates of the forward and reverse reactions are equal

Which one of the following will change the value of an equilibrium constant?

changing temperature

Amphoteric Molecules

Can Function as either acids or bases, depending on reaction conditions.

Brønsted-Lowry Acid =

Brønsted-Lowry Base =

Proton donor

Proton acceptor

Nitric acid is a strong acid. This means that

HNO3 dissociates completely to H+ (aq) and NO3- (aq) when it dissolves in water

Which one of the following processes produces a decrease in the entropy of the system?

freezing water to form ice

A reaction that is not spontaneous at low temperature can become spontaneous at high temperature if ΔH is __________ and ΔS is __________.

+,+

For a reaction to be spontaneous under standard conditions at all temperatures, the signs of ΔH° andΔS° must be __________ and __________, respectively

-,+

If ΔG° for a reaction is greater than zero, then

K<1

A reducing agent does what with electrons

gives up electrons causing another substance to be reduced

oxidation

loss of electrons

reduction

gain of electrons

Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative

K>1

density equation:

d=(MW)(P)/RT

ideal gas

PV=nRT

Charles law

v1/t1=v2/t2

combined

p1v1/t1=p2v2/t2

Gay lus

p1/t1=p2/t2

kinetic molecular theory:

molecules are in random motion, elastic collisions, volume of molecules too small to notice, no attractive forces

Urms=

sqrt(3RT/Mkg), with R=8.314

effusion

leaking out small hole

Grahams Law:

rate gas A/rate gas B = sqrt(MWb/MWa)

IMF strength from weakest to strongest

London dispersion, dipole-dipole, hydrogen, ionic

London dispersion

everything has London dispersion, stronger if MW is high

dipole-dipole

polar molecules, stronger is big EN difference

Hydrogen bonding

H-F

H-O

H-N

Ionic bonding

polar, ionic pair

higher pressure means

higher BP

liquid heat capacity

4.184 j/g*C

critical point

can't tell the difference between phases, where a gas will never turn to a liquid

molecular crystals

soft, low melting points, weak IMFs, don't conduct electricity

covalent crystals

hard, high melting points, poor conductors except in silicon

metallic crystals

hard-> soft, high-> low melting point, luster, conduct heat and electricity well

ionic crystals

hard, brittle, high melting points, non conductors as solids good conductors when melted

homogeneous mixture

2 or more substances

heterogenous mixture

1 substance

solvent:

the one you have the most of

solute:

the one you have the least of

solubility rule

like dissolve like

temp effect:

solubility increases w/ temp almost always

Henry's law:

concentration proportional to partial pressure

molality

moles solute/kg solvent

mole fraction

moles solute/total moles

mass %

mass solute/total mass x100

colligative properties

vapor pressure lowering

freezing point depression

boiling point elevation

osmotic pressure

osmotic pressure

pi=MRT

colloid

look like solution but not, they're heterogenous