At equilibrium concentration quotient is equal to the equilibrium constant.

Answer

To determine whether the statement "At equilibrium, the concentration quotient is equal to the equilibrium constant" is true or false, we can analyze the concepts of the concentration quotient (Q) and the equilibrium constant (K).

### Step-by-Step Solution:

1. **Understanding Q and K**:
- The concentration quotient (Q) is defined as the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their respective coefficients in the balanced chemical equation.
- The equilibrium constant (K) is similar to Q but is specifically calculated using the concentrations of the reactants and products at equilibrium.

2. **Writing the Expression for Q**:
- For a general reaction:
\[ aA + bB \rightleftharpoons cC + dD \]
- The expression for Q is:
\[ Q = \frac{[C]^c [D]^d}{[A]^a [B]^b} \]
- Here, [C], [D], [A], and [B] are the concentrations of the respective species at any point in time.

3. **Writing the Expression for K**:
- The expression for K at equilibrium is the same as that for Q, but it uses the equilibrium concentrations:
\[ K = \frac{[C]_{eq}^c [D]_{eq}^d}{[A]_{eq}^a [B]_{eq}^b} \]
- Here, \([C]_{eq}\), \([D]_{eq}\), \([A]_{eq}\), and \([B]_{eq}\) are the equilibrium concentrations.

4. **Equilibrium Condition**:
- At equilibrium, the concentrations of the reactants and products no longer change, and thus, if we calculate Q using the equilibrium concentrations, we find that:
\[ Q = K \]

5. **Conclusion**:
- Since at equilibrium, the concentration quotient (Q) is equal to the equilibrium constant (K), the statement "At equilibrium, the concentration quotient is equal to the equilibrium constant" is **True**.

### Final Answer:
The statement is **True**.