Question

For a reversible reaction, if the concentrations of the reactants are doubled, the equilibrium constant will be

• A. one-fourth
• B. halved
• C. doubled
• D. he same

Answer 1

Answer: (D)

Consider a hypothetical change, $A+B\rightleftharpoons C+D$
For this reaction, $K_{eq}=\frac{[C][D]}{[A][B]}$
For the above reaction if concentration of reactants are doubled then the rate of forward reaction increases for a short time but after sometime equilibrium will established. So, concentration has no effect on equilibrium constant. It remains unchanged after increasing the concentration of reactants.