5.2.2 Enthalpy and Entropy

Question 1

Define entropy

Answer 1

A measure of the dispersal of energy in a system which is greater when the system is more disordered

Question 2

What is the symbol of entropy

Answer 2

S

Question 3

Solid or gas, which is more disordered

Answer 3

gas

Question 4

What is the unit of standard entropy

Answer 4

J K-1 mol -1

Question 5

How does temperature affect entropy?

Answer 5

The greater temperature particles have more energy and move more. Thus the arrangement of particles become more random. more random arrangement = higher entropy

Question 6

When a solid ionic lattice is dissolved in solution, what happens to entropy

Answer 6

Entropy increases because the ions are more disordered

Question 7

How does change in number of gas molecules in a reaction affect entropy?

Answer 7

Increase in no. gas molecules = increase in entropy

Decrease in no. gas molecules = decrease in entropy

Question 8

Write the equation used to calculate entropy change

Answer 8

Entropy change = S products - S reactants

Question 9

Write the Gibbs free energy equation and state what each symbol means?

Answer 9

Delta G = Delta H - T Detla S

Question 10

For a reaction to occur spontaneously (feasible) , Delta G must be positive or negative?

Answer 10

Negative

Question 11

What are the limitations of the predictions of feasibility made by using delta G?

Answer 11

Reaction ay have high activation energy

Rate of reaction may be very slow