$C{O_2}(s) \to C{O_2}(g)$
${I_2} \to {I_2}(aq)$
${N_2}(g) + 3{H_2}(g) \to 2N{H_3}(g)$
${N_2}(g) + 3{H_2} \leftrightarrow 2N{H_3}(g)$
$\Delta S = 2\Delta {S_{N{H_3}}} - [\Delta {S_{{N_2}}} + 3\Delta {S_{{H_2}}}]$
There is decrease in number of moles of $NH_3$ entropy is decreasing.