Question

Consider the following equilibrium: 2SO2(g) + O2(g) 2SO3(g) Which of the following is a correct equilibrium expression? Keq=[SO3][SO2][O2] Keq=[SO3]2[SO2]2[O2] Keq=[SO2][O2][SO3] Keq=[SO2]2[O2][SO3]2

Answer 1

Answer : Option B) $K_{eq} = \frac{[SO_{3}]^{2} }{[SO_{3}]^{2} . [O_{3}]^{2}}$

Explanation : The equilibrium constant is often expressed in terms of the molar concentration of products divided by the product of molar concentrations of reactants.

So, $K_{eq} = \frac{[products]}{[reactants]}$.

Now, here in the given reaction of  

$2SO_{2} + O_{2} ----\ \textgreater \ 2SO_{3}$

So, we have the equation for equilibrium as $K_{eq} = \frac{[SO_{3}]^{2} }{[SO_{3}]^{2} . [O_{3}]^{2}}$