Chapter 18, Problem 18.45SP

Predict the sign of $\Delta$ S in the system for each of the following reactions:

(a) ${\text{PCl}}_{\text{5}}\left(\text{s}\right)\stackrel{}{\to }{\text{PCl}}_{\text{3}}\left(l\right)+{\text{ Cl}}_{\text{2}}\left(\text{g}\right)$

(b) ${\text{CH}}_{\text{4}}\left(\text{g}\right)+{\text{ 2 O}}_{\text{2}}\left(\text{g}\right)\stackrel{}{\to }{\text{CO}}_{\text{2}}\left(\text{g}\right)+{\text{ 2 H}}_{\text{2}}\text{O}\left(l\right)$

(c) ${\text{2 H}}_{\text{3}}{\text{O}}^{+}\left(\text{aq}\right)+{\text{ CO}}_{\text{3}}^{2-}\left(\text{aq}\right)\stackrel{}{\to }{\text{CO}}_{\text{2}}\left(\text{g}\right)+{\text{ 3 H}}_{\text{2}}\text{O}\left(l\right)$

(d) $\text{Mg}\left(\text{s}\right)+{\text{ Cl}}_{\text{2}}\left(\text{g}\right)\stackrel{}{\to }{\text{ MgCI}}_{\text{2}}\left(\text{s}\right)$