Question

If concentration quotient, Q is greater than ${K_C}$ , the net reaction is taking place in backward direction
A.True
B.False
C.Cannot be determined
D.none of the above

Answer 1

If concentration quotient, Q is greater than $Kc$ ​, then the net reaction is taking place in backward direction because the concentration of products is higher than the equilibrium concentration and the concentration of reactants is lower than the equilibrium concentration and to attain the equilibrium, more of the products will be consumed and more of the reactants will be formed.

Complete answer:
The value of the reaction quotient Q is greater than the value of the equilibrium constant K. Hence, the concentration of products is much higher than the equilibrium concentration of products and the concentration of reactants is much smaller than the equilibrium concentration of reactants. Hence, the equilibrium will shift in the backward direction.
Thus, it is true that If concentration quotient, Q is greater than ${K_C}$ , the net reaction is taking place in a backward direction.
In the case where $Q > {K_C}$ , concentration quotient, Q is greater than ${K_C}$ , this suggests that we have more product present than we would have at equilibrium. Therefore, the reaction will try to use up some of the excess product and favour the reverse reaction to reach equilibrium.

Therefore, the correct answer is option (A).

Note: ${K_C}$ can be used to calculate the final concentrations at equilibrium for a reaction and the natural progression of the reaction, from left to right or from right to left. A simple relationship between ${K_C}$ and the reaction quotient, known as $Qc$ can help. The reaction quotient, Q, expresses the relative ratio of products to reactants at a given instant.