question_answer

One mole of \[S{{O}_{3}}\] was placed in a one litre reaction flask at a given temperature when the reaction equilibrium was established in the reaction. \[2S{{O}_{3}}\rightleftharpoons 2S{{O}_{2}}+{{O}_{2}}\]. The vessel was found to contain 0.6 mole of\[S{{O}_{2}}\]. The value of the equilibrium constant is

A) 0.36                 

B) 0.675

C) 0.45                 

D) 0.54

Correct Answer: B

Solution :

[b] Initial At equilibrium \[\therefore 2\alpha =0.6,\text{ }\therefore \alpha =0.3\] \[\left[ S{{O}_{3}} \right]=1-2\alpha =1-0.6=0.4\] \[\left[ S{{O}_{2}} \right]=2\alpha =0.6\] \[\left[ {{O}_{2}} \right]=\alpha =0.3\] \[{{K}_{eq}}=\frac{\alpha \times {{(2\alpha )}^{2}}}{{{(1-2\alpha )}^{2}}}=\frac{0.3\times 0.6\times 0.6}{0.4\times 0.4}=0.675\]