Lecture 2: Gases, Kinetics, & Chem Equilib

Question 1

measure of the average kinetic energy of particles in a system
SI Unit: Kelvin (K)

Answer 1

temperature

Question 2

loose collection of weakly attracted atoms or molecules moving rapidly in random direction

Answer 2

gas

Question 3

0ºC, 1 atm,

Answer 3

standard temperature and pressure

Question 4

freezing point of H20 in Kelvin

Answer 4

273 degrees Kelvin

Question 5

boiling point of H2O in Kelvin

Answer 5

373 degrees kelvin

Question 6

an ideal gas lacks certain real gas characteristics present in a real gas. Ideal gas molecules:

1. Have ZERO VOLUME
2. Exert no forces other than repulsive forces due to collisions
3. Completely elastic collisions
4. Avg Kinetic Energy of gas molecules is directly proportional to the temperature of the gas

Answer 6

kinetic molecular theory

Question 7

Equation: Ideal Gas Law

Answer 7

PV = nRT
Note: P = pressure in atmospheres
V = volume in liters
n = number of moles of gas
R = universal gas constant
T = temperature

Question 8

SI Units: Pressure

Answer 8

Pascal (N / m^2)
1 atm
760 mm Hg = 760 torr

Question 9

Increased temperature, increased number of moles, and decreased volume will cause the pressure of a gas to ______

Answer 9

increase

Question 10

In a gas, temperature and pressure are ________.

Answer 10

directly proportional

Question 11

in a gas, pressure is ______ related to volume.

Answer 11

inversely

Question 12

Increasing the number of moles of gas will _______ the pressure, due to more collisions between molecules.

Answer 12

increase

Question 13

Three conditions of an ideal gas:

Answer 13

1. No intermolecular forces (all K.E. directly applied to pressure)
2. Molecules have no volume
3. Collisions are perfectly elastic; No K.E. lost during collisions b/w these particles

Question 14

Standard molar volume for any ideal gas

Answer 14

22.4 Liters

Question 15

amount of pressure contributed by any gas in a gaseous mixture

Answer 15

partial pressure

Question 16

Equation: Partial pressure

Answer 16

P(a) = X(a) * P(total)

Note: X(a) = mole fraction of gas “a”

Question 17

the total pressure exerted by a gaseous mixture is the sum of the partial pressures of each of its gases
i.e. Each gas behaves like it is in a container by itself, so all partial pressures can add together

Answer 17

Dalton’s law

Question 18

Equation: Dalton’s Law

Answer 18

P(total) = P1 + P2 + P3…

Question 19

Equation: Average translational kinetic energy for an ideal gas

Answer 19

K.E. (avg) = (3/2) * R * T

Question 20

the gas molecules of each gas in any gaseous mixture must have the same _______

Answer 20

average kinetic energy

Question 21

Equation: Graham’s Law (ratio of rms velocities of two gases in a homogenous mixture)

Answer 21

v1 / v2 = √m2 / √m1

Question 22

spreading of a gas from high pressure to very low pressure through a pinhole

Answer 22

effusion

Question 23

Equation: rates of effusion (or diffusion) for two gases at the same temp

Answer 23

effusion rate 1 / effusion rate 2 = √M2 / √M1

Question 24

spreading of one gas into another gas or into empty space

Answer 24

diffusion

Question 25

the degree to which a real gas deviates from an ideal gas depends on magnitude of ______ and the ____ of the particles

Answer 25

intermolecular forces; size of particles

Question 26

Since molecules of a real gas to have volume, their volume must be ______ to the ideal volume

Answer 26

added; V(real) > V(ideal)

Question 27

Because molecules in a real gas are pulled inward by attractive forces, molecules in a real gas slow before colliding with container walls and strike w/ less force than predicted by KMT. A real gas exerts ____ pressure than an ideal gas.

Answer 27

Less pressure; P(real)

Question 28

Equation: Rate Law for forward reaction

Answer 28

rate (forward) = k(f) * [A]^a * [B]^b | Note: k(f) = rate constant for the forward reaction

Question 29

first order reaction rate

Answer 29

rate of reaction is directly proportional to the concentration of the reactant which concentration changed that reactant receives an exponent of 1 and is first order w/ respect to that reactant

Question 30

second order reaction rate

Answer 30

rate of reaction is proportional to the square of the concentration of that reactant; rate of reaction increases by a factor of 4 (quadruples) the reactant receives an exponent of 2 and the reaction is second order with respect to B

Question 31

zero order reaction rate

Answer 31

if the concentration of a reactant is changed but does not change the rate of the reaction, the rate is independent of the concentration of that reactant the reactant receives an exponent of zero in the rate law and the reaction is zero order with respect to C.

Question 32

Find the overall reaction order of a chemical reaction by ____

Answer 32

adding the exponents for the rate law for each reactant

Question 33

Equation: Reaction Quotient

Answer 33

Q = Products^(coefficients) / Reactants^(coefficients)

Question 34

used to predict the direction in which a reaction will proceed can have any positive value describes reactions not at equilibrium

Answer 34

reaction quotient (Q)

Question 35

relationships between a chemical equation and the equilibrium constant -Don't use solids or pure liquids (water) in this law

Answer 35

law of mass action

Question 36

Equation: Law of mass action

Answer 36

K = [C]^c * [D]^d / [A]^a * [B]^b = Products^coefficients / Reactants ^coefficients