Entropy (Simplified) Practice Problems

Is ΔS positive or negative for the synthesis of liquid ammonia (NH₃)? 

3 H₂(g) + N₂(g) → 2 NH₃(l)  ΔH = −38.4 kcal/mol (−161 kJ/mol)

The ΔH of the following reaction is 228 kcal/mol (953 kJ/mol). 

2 Cs(g) + Br₂(l) → 2 CsBr(s)

Does the entropy of the reaction decrease or increase? Why?

The ΔH of the following reaction is +68.35 kcal/mol (+286 kJ/mol). 

Ag₂S(s) → 2 Ag⁺(aq) + S²⁻(aq)

Is the entropy of the reaction increasing or decreasing?

Does the following process have increasing or decreasing entropy? Why? 

spinning several cotton fibers into a ball of yarn

Determine the system whose entropy is increasing. 

Does the entropy of the following process increase or decrease? 

2 PCl₃(g) + O₂(g) → 2 POCl₃(g)

True or False. Entropy decreases when protein complexes are metabolized by the body into amino acids.