Chapter 17

Question 1

define 0th law of thermodynamics

Answer 1

if two objects are in thermal equilibrium with a third object then they are in thermal equilibrium with each other

Question 2

difference between heat and temp?

Answer 2

heat is the flow of energy caused by a temp difference but temp is a measure of the average KE per molecule

Question 3

what does the amount of heat flow depend on?

Answer 3

size, specific heat capacity and temp difference

Question 4

what is Dalton’s law of partial pressures

Answer 4

Ptotal = P1 + P2

Question 5

what is the average KE of a molecule?

Answer 5

K = 1.5kT

Question 6

what is the average KE of a mole?

Answer 6

K = 1.5RT

Question 7

give two equations for average (v^2)

Answer 7

(v^2)av = (3RT/M) = (3KT/m)

Question 8

what is the relationship between Vrms and (V^2)av?

Answer 8

Vrms = sqrt[(V^2)av]

Question 9

what is the equipartition theorem?

Answer 9

when a substance is in equilibrium, there is an average energy of 0.5kT per molecule or 0.5RT per mole associated with each degree of freedom

Question 10

what is the difference between n and N?

Answer 10

n = number of moles
N = number of molecules
N=nNa

Question 11

what is the difference between M and m?

Answer 11

m = mass of a molecule (g)
M = mass of a mole (g/mol)
M = mNa

Question 12

what is Vmax?

Answer 12

most probable speed, Vmax = sqrt(2kT/m) = sqrt(2RT/M)

Question 13

what does the mean free path depend on?

Answer 13

number of models and the size of molecules:

λ = 1 / sqrt(2) * (N/V) π d^2

Question 14

what is the collision time?

Answer 14

the average time between collisions:

λ = Vav * τ