Final answer:
To calculate the standard entropy change (ΔS°) for the reaction of NH3(g) with HCl(g) to form NH4Cl(s), use standard molar entropy values from data tables and apply them in the entropy change formula.
Step-by-step explanation:
The question involves calculating the standard entropy change (ΔS°) for the reaction where ammonia (NH3(g)) reacts with hydrogen chloride (HCl(g)) to form ammonium chloride (NH4Cl(s)). To calculate the entropy change for this reaction, we use the standard molar entropies (S°) for each substance involved in the reaction.
The formula to calculate ΔS° is:
ΔS° = Σ S°(products) − Σ S°(reactants)
You would look up the standard molar entropy values in a data table (like Appendix G) for NH3(g), HCl(g), and NH4Cl(s). Then, plug those values into the formula to find ΔS° for the reaction by subtracting the sum of the entropies of the reactants from the sum of the entropies of the products. As solid substances typically have lower entropy than gases, you can expect the entropy change to be negative, given that two gases are forming a solid in this reaction.