MCQ
The process with negative entropy change is
  • A
    Dissociation of $CaSO_4(s)$ to $CaO(s)$ and $SO_3(g)$
  • B
    Sublimation of dry ice
  • C
    Dissolution of iodine in water
  • Synthesis of ammonia from $N_2$ and $H_2$

Answer

Correct option: D.
Synthesis of ammonia from $N_2$ and $H_2$
d
$CaS{O_4}(s) \to CaO(s) + S{O_3}(g)$

$C{O_2}(s) \to C{O_2}(g)$

${I_2} \to {I_2}(aq)$

${N_2}(g) + 3{H_2}(g) \to 2N{H_3}(g)$

${N_2}(g) + 3{H_2} \leftrightarrow 2N{H_3}(g)$

$\Delta S = 2\Delta {S_{N{H_3}}} - [\Delta {S_{{N_2}}} + 3\Delta {S_{{H_2}}}]$

There is decrease in number of moles of $NH_3$ entropy is decreasing.

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