Question

For the reaction $2Cl(g) \rightarrow Cl_2(g)$, the correct option is:

• A. $\Delta_r H > 0$ and $\Delta_rS > 0$
• B. $\Delta_r H > 0$ and $\Delta_rS < 0$
• C. $\Delta_r H < 0$ and $\Delta_rS > 0$
• D. $\Delta_r H < 0$ and $\Delta_r S < 0$

Answer 1

Answer: (D)

$2 C l(g) \longrightarrow C l_2(g)$
As the process involves bond formation $\Delta H=-v e$ and as the number of gaseous particles are decreasing in the reaction $\Delta S$ is also $-v e$
i.e., $\Delta_r H< 0$ and $\Delta_r S< 0$