5.7 Entropy

Question 1

What is entropy?

Answer 1

A measure of how the available energy is distributed among the particles.

Question 2

How can entropy be related to the disorder in the system?

Answer 2

The more disordered the system the more ways there are of distributing the energy and the higher the energy.

Question 3

What are the units of standard entropy?

Answer 3

Jk-1mol-1

Question 4

What is the order of increasing entropy in the solid, liquid and gas state?

Answer 4

entropy of solid < entropy of liquid < entropy of gas

Question 5

Why does a gas have a higher entropy?

Answer 5

The particles in a gas are moving around more randomly and the energy can be distributed in more ways.

Question 6

How it be worked out from a chemical reaction can an increase or decrease in entropy takes place?

Answer 6

By looking at the number of moles of gas, increase in number of moles of gas means increase in entropy, decrease in the number of moles of gas means a decrease in entropy.

Question 7

How can the change in entropy be worked out?

Answer 7

Sum of entropy of products - sum of entropy of reactants