Chapter 18, Problem 57GQ

When vapors from hydrochloric acid and aqueous ammonia come in contact, they react, producing a white “cloud” of solid NH₄C1 (Figure 18.9).

HCI(g) + NH₃(g) ⇄ NH₄Cl(s)

Defining the reactants and products as the system under study:

1. (a) Predict whether ΔS°(system), ΔS°(surroundings), ΔS°(universe), Δ_rH°, and Δ_rG° (at 298 K) are greater than zero, equal to zero, or less than zero; and explain your prediction. Verify your predictions by calculating values for each of these quantities.
2. (b) Calculate the value of K_p for this reaction at 298 K.