MOaD 10

Question 1

Entropy, S, definition

Answer 1

the ‘quality’ of energy that leads to spontaneous change,
it is a direct measure of energy to flow towards a more diffuse state.

Question 2

entropy formula

Answer 2

S = kB ln W

Question 3

what is W in the entropy formula?

Answer 3

W is the number of ways of arranging a given system.

Question 4

how to calculate W

Answer 4

factorial

Question 5

entropy of an expanding gas formulas

Answer 5

ΔS = kB ln(Vf / Vi)N
n is the moles of gas
or
ΔS = nR ln(Vf / Vi)

Question 6

formula for the maximum work

Answer 6

w = -qrev = - RT ln(Vf / Vi)

Question 7

formula for entropy change from the maximum work

Answer 7

ΔS = qrev / T

Question 8

the entropy change has an inverse temperature dependence.

Answer 8

The equation for the 2nd LoTD shows that ……….

Question 9

At low T,,,,,,,

Answer 9

, few energy levels are populated, so giving heat to the system (+q) has a relatively large effect.

Question 10

at high T……..

Answer 10

many levels are already accessible, so adding extra +q has a relatively much smaller effect. So ΔS is inversely proportional to T.