Gibbs Free Energy

Question 1

The combination of a system’s enthalpy and entropy is called what?

Answer 1

Gibbs free energy

Question 2

What is the formula for change in Gibbs free energy?

Answer 2

ΔG = ΔH - TΔS

Question 3

What does free energy change (ΔG) measure?

Answer 3

The spontaneity of a process and the useful energy available from it

Question 4

If ΔG is positive, is the process spontaneous?

Answer 4

No, it is spontaneous in the reverse direction

Question 5

If ΔG is negative, is the process spontaneous?

Answer 5

Yes

Question 6

If ΔG = 0, is the process spontaneous?

Answer 6

The system is at equilibrium

Question 7

If ΔH is negative and ΔS is positive, when is the reaction spontaneous?

Answer 7

Always

Question 8

If ΔH is positive and ΔS is negative, when is the reaction spontaneous?

Answer 8

Never

Question 9

For ΔG = ΔH - TΔS, at a low temperature, is enthalpy or entropy change more important?

Answer 9

ΔH

Question 10

For ΔG = ΔH - TΔS, at a high temperature, is enthalpy or entropy change more important?

Answer 10

ΔS

Question 11

What is the difference between ΔG and ΔG°?

Answer 11

ΔG° is when Q = 1

Question 12

What is the equation for ΔG using Q and K?

Answer 12

ΔG = RT ln(Q/K)

Question 13

What is the equation for ΔG° using K?

Answer 13

ΔG° = -RT ln(K)

Question 14

What is the equation for ΔG using ΔG° and Q?

Answer 14

ΔG = ΔG° + RT ln(Q)