Practice question
Question
For the reaction 2A(g) <=> B(g) + C(g) , if Kc = 0.25 and at equilibrium [B] = 0.1 M , [C] = 0.1 M , what is [A] ?
Explanation
Kc = ([B][C]/[A]²) = 0.25 . Substituting, 0.25 = ((0.1)(0.1)/[A]²) = (0.01/[A]²) , [A]² = (0.01/0.25) = 0.04 , [A] = 0.2 M .