91Ó°ÊÓ

Name two processes for which you could determine an enthalpy change.

Explain the meanings of \(H, \Delta H,\) and \(\Delta H_{f}^{o}\)

State Hess's law. How is it used?

Which thermodynamic property of a food is of interest to nutritionists? Why?

Why is entropy described as an extensive property?

Explain how a comprehensive table of standard Gibbs energies of formation can be used to determine the spontaneity of any chemical reaction.

What information is needed to be certain that a chemical reaction is nonspontaneous?

You need 70.2 \(\mathrm{J}\) to raise the temperature of 34.0 \(\mathrm{g}\) of ammonia, \(\mathrm{NH}_{3}(g),\) from \(23.0^{\circ} \mathrm{C}\) to \(24.0^{\circ} \mathrm{C}\) . Calculate the molar heat capacity of ammonia.

Calculate \(C\) for indium metal given that 1.0 mol In absorbs 53 J during the following process. $$\operatorname{In}(s, 297.5 \mathrm{K}) \longrightarrow \operatorname{In}(s, 299.5 \mathrm{K})$$

Given the entropy change for the first two reactions below, calculate the entropy change for the third reaction below. \begin{equation} \begin{array}{c}{\mathrm{S}_{8}(s)+8 \mathrm{O}_{2}(g) \rightarrow 8 \mathrm{SO}_{2}(g) \Delta S=89 \mathrm{J} / \mathrm{K}} \\ {2 \mathrm{SO}_{2}(s)+\mathrm{O}_{2}(g) \rightarrow 2 \mathrm{SO}_{3}(g) \Delta S=-188 \mathrm{J} / \mathrm{K}} \\ {\mathrm{S}_{8}(s)+12 \mathrm{O}_{2}(g) \rightarrow 8 \mathrm{SO}_{3}(g) \Delta S=?}\end{array} \end{equation}