Question

Just before attaining the chemical equilibrium:

• A. rate of forward reaction decreases & rate of backward reaction increases
• B. rate of forward reaction decreases & rate of backward reaction decreases
• C. no change in the rates of forward & backward reaction
• D. rate of forward reaction equals the rate backward reaction

Answer 1

The correct option is A rate of forward reaction decreases & rate of backward reaction increases

Just before attaining the chemical equilibrium rate of forward reaction decreases & rate of backward reaction increases.
Just before attaining the chemical equilibrium, the reactant concentration is slightly more than the equilibrium concentration and the product concentration is slightly less than the equilibrium concentration.
Hence, as reactants are consumed during the course of the reaction, the reactant concentration decreases and the rate of forward reaction decreases.
Similarly as products are formed during the course of the reaction, the product concentration increases and the rate of backward reaction increases.