Calculate the total standard entropy change in each of the following reactions using the standard molar entropy values given here.

(Values for S^θin J K^–1 mol^–1: C(graphite) = 5.700,

C₂N₂(g) = 242.1, C₃H₈(g) = 269.9,

CO₂(g) = 213.6, H₂(g) = 130.6,

H₂O(l) = 69.90, H₂S(g) = 205.7, 

N₂(g) = 191.6, O₂(g) = 205.0,

P(s) = 41.10, P₄O₁₀(s) = 228.9, S(s) = 31.80)

a. S(s) + H₂(g) → H₂S(g)                                      ΔH^θreaction= –20.6 kJ mol^–1

b. 2C(graphite) + N₂(g) → C₂N₂(g)                    ΔH^θreaction= +307.9 kJ mol^–1

c. 4P(s) + 5O₂(g) → P₄O₁₀(s)                              ΔH^θreaction= –2984.0 kJ mol^–1

d. C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)         ΔH^θreaction= –2219.2 kJ mol^–1