Question

Part A

Choose all the true statements from the list below.

1) It is impossible to freeze ethanol because the change in entropy of the system is negative.

2) Liquid water has a lower entropy than liquid benzene at 25°C because of hydrogen bonding in water.

3) freezing water is possible only if the entropy of the surroundings increases

4) Ice at 0°C has a higher entropy than liquid water at 0°C because the density of ice is lower than the density of water.

5) Reactions that involve only gases always have a positive change in entropy

6) Entropy is the main driving force in the formation of the DNA double helix.

7) All elements in their standard states have an entropy of zero at 25°C.

8) Evaporating a liquid has always a positive change in entropy

9) Binding a substrate to an enzyme always lowers the entropy because the substrate loses translational and rotational degrees of freedom.

Answer 1

1- false

Possible because total entropy change i.e of system+surrounding would be positive

2. True

As attractive forces increase the entropy decrease.

3. True

Because total entropy change should be positive as that of system is negative.

4. False

Ice have lower entropy then water.

5. False

Only if number of gaseous products are more then reactants.

6. False

H-bonding Attraction develop so entropy decrease

7. False

Entropy is zero for a perfectly crystalline substance at T=0k

8. True

Heat is absorbed by system

9. True

As attractive forces increase the entropy decrease