Question

At certain temperature and a total pressure of $ \text{1}{{\text{0}}^{\text{5}}}\,\text{Pa,} $ iodine vapours contains 40% by volume of iodine atoms. $ {{K}_{p}} $ for the equilibrium, $ {{I}_{2}}(g)2I(g); $ will be

• A. $ 0.67 $
• B. $ 1.5 $
• C. $ 2.67\times {{10}^{4}} $
• D. $ 9.0\times {{10}^{4}} $

Answer 1

Answer: (C)

Partial pressure of iodine atoms
$ ({{p}_{1}})=\frac{40}{100}\times {{10}^{5}} $
$ =0.40\times {{10}^{5}}\,Pa $
Partial pressure of $ {{l}_{2}}(p{{l}_{2}}) $
$ =\frac{60}{100}\times {{10}^{5}}Pa $
$ =0.60\times {{10}^{5}}Pa $
$ \therefore $ $ {{K}_{p}}=\frac{p_{l}^{2}}{{{p}_{{{l}_{2}}}}}=\frac{{{(0.40\times {{10}^{5}})}^{2}}}{0.60\times {{10}^{5}}} $
$ =2.67\times {{10}^{4}} $