1. Predict the sign of delta S for each process.

(a) the boiling of water 

(b) I2(g)->I2(s)

(c) CaCO3(s)->CaO(s)+CO2(g)

2. Calculate the change in entropy that occurs in the system when 10.0g of acetone (C3H6O) vaporizes from a liquid to a gas at its normal boiling point (56.1 degrees C)

3. Consider the reaction between nitrogen and oxygen gas from dinitrogen monoxide. 

2N2(g)+O2(g) -> 2N2O(g) 

delta Hrxn= +163.2kJ

a) Calculate the entropy change in the surroundings when this reaction occurs at 25 degrees C

b) Determine the sign of the entropy change for the system.

c) Determine the sign of the entropy change for the universe. Is the reaction spontaneous?

• For a reaction, delta H rxn= -107 kJ and delta S rxn = 285 J/K. At what temperature is the change in entropy for this reaction equal to the change in entropy for the surroundings?