For each reaction, calculate ΔH°rxn, ΔS°rxn, and ΔG°rxn at 25 °C and state whether the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 °C? b. NH4Cl(s) → HCl(g) + NH3(g) c. 3 H2(g) + Fe2O3(s) → 2 Fe(s) + 3 H2O(g)

Verified step by step guidance

1. <insert step 1: Identify the standard enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°) for each reaction.>
2. <insert step 2: Use standard enthalpies of formation (ΔH°f) to calculate ΔH°rxn for each reaction. The formula is ΔH°rxn = ΣΔH°f(products) - ΣΔH°f(reactants).>
3. <insert step 3: Use standard molar entropies (S°) to calculate ΔS°rxn for each reaction. The formula is ΔS°rxn = ΣS°(products) - ΣS°(reactants).>
4. <insert step 4: Calculate ΔG°rxn using the equation ΔG°rxn = ΔH°rxn - TΔS°rxn, where T is the temperature in Kelvin (298 K for 25 °C).>
5. <insert step 5: Determine spontaneity by checking the sign of ΔG°rxn. If ΔG°rxn is negative, the reaction is spontaneous. If not, consider how temperature affects spontaneity: if ΔH° and ΔS° are both positive, increasing temperature may make the reaction spontaneous; if both are negative, decreasing temperature may help.>