question_answer 1)

A sample of pure \[PC{{l}_{5}}\] was introduced into an evacuated vessel at 473 K. After equilibrium was reached, the concentration of\[PC{{l}_{5}}\]was found to be\[0.5\times {{10}^{-1}}mol\,{{L}^{-1}}\]. If \[{{K}_{c}}\] is \[8.3\times {{10}^{-3}}\], what are the concentrations of\[PC{{l}_{3}}\] and\[C{{l}_{2}}\] at the equilibrium?

Answer:

The given reaction: \[\underset{At\,equilibrium}{\mathop{{}}}\,\underset{0.05}{\mathop{PC{{l}_{5}}(g)}}\,\rightleftharpoons \underset{x}{\mathop{PC{{l}_{3}}(g)}}\,+\underset{x}{\mathop{C{{l}_{2}}(g)}}\,\] \[{{K}_{c}}=\frac{[PC{{l}_{3}}][C{{l}_{2}}]}{[PC{{l}_{5}}]}\] \[8.3\times {{10}^{-3}}=\frac{x\times x}{0.05}\] \[x=0.02\] \[[PC{{l}_{3}}]=[C{{l}_{2}}]=0.02M\]