Question

For the reaction, $PC{l}_5\left(g\right)\to PC{l}_3\left(g\right)+C{l}_2\left(g\right),$ the correct option is:

• A. ${\Delta }_{r}H=0\text{and}{\Delta }_{r}S<0$
• B. ${\Delta }_{r}H<0\text{and}{\Delta }_{r}S=0$
• C. ${\Delta }_{r}H<0\text{and}{\Delta }_{r}S>0$
• D. ${\Delta }_{r}H>0\text{and}{\Delta }_{r}S>0$

Answer 1

The correct option is D ${\Delta }_{r}H>0\text{and}{\Delta }_{r}S>0$

• Dissociation of $PC{l}_5\left(g\right)$ is endothermic process, So ${\Delta }_{r}H>0$
• Since, $\Delta n_g>0,$ So, ${\Delta }_{r}S>0$