Enthalpy, Entropy and Gibbs free energy

Which reaction has the greatest increase in entropy?

• 2H₂0 (l) --> 2H_{2 (g)} + O_{2 (g)}

• 2H₂O(g)--> 2H₂(g) + O₂(g)

• H₂O(g) --> H₂O(l)

• H₂O(l) H₂O(s)

Which process is accompanied by a decrease in entropy?

• boiling of water

• condensing of water vapor

• subliming of iodine (solid directly to gas)

• melting of ice

Systems in nature tend to undergo changes toward

• lower energy and less disorder

• lower energy and more disorder

• higher energy and less disorder

• higher energy and more disorder

Given the change of phase:

CO₂(g) —> CO₂(s)

As CO₂(g) changes to CO₂(s), the entropy of the system

• decreases

• increases

• remains the same

Which phase change represents a decrease in entropy?

• solid to liquid

• gas to liquid

• liquid to gas

• solid to gas

Which sample has the lowest entropy?

• 1 mole of KNO3(l)

• 1 mole of KNO3(s)

• 1 mole of H2O(l)

• 1 mole of H2O(g)

Identify whether the following result in an increase or decrease in entropy:

Gas --> Liquid --> solid

• increase

• decrease

Identify whether the following result in an increase or decrease in entropy:

3 moles of gas (on reactant side) --> 6 moles of gas (product)

• increase

• decrease

Identify whether the following result in an increase or decrease in entropy:

Vaporization

• increase

• decrease

The following statements are true for entropy EXCEPT

• entropy is the measure of molecular disorder

• entropy is greater if matter is more dispersed

• gases have more entropy than liquids of the same substance and temperature

• lowering the temperature causes entropy to increase.