Which of the following is correct if reaction quotient `(Q)=1`?

Options

A. `DeltaG=0`
B. `DeltaG^(@)=0`
C. `DeltaGg tDeltaG^(@)`
D. `DeltaG=DeltaG^(@)`

Answer

To solve the question regarding the reaction quotient \( Q \) and its implications when \( Q = 1 \), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Reaction Quotient (Q)**:
The reaction quotient \( Q \) is a measure of the relative concentrations of products and reactants at any point in time during a chemical reaction. It helps us determine the direction in which the reaction will proceed.

2. **Given Condition**:
We are given that \( Q = 1 \). This means that the concentrations of products and reactants are equal at this point.

3. **Relating Gibbs Free Energy (ΔG) and Standard Gibbs Free Energy (ΔG°)**:
The relationship between the Gibbs free energy change (\( \Delta G \)), standard Gibbs free energy change (\( \Delta G° \)), and the reaction quotient (\( Q \)) is given by the equation:
\[ \Delta G = \Delta G° + RT \ln Q \]
where \( R \) is the universal gas constant and \( T \) is the temperature in Kelvin.

4. **Substituting \( Q = 1 \)**:
If we substitute \( Q = 1 \) into the equation, we have:
\[ \Delta G = \Delta G° + RT \ln(1) \]
Since \( \ln(1) = 0 \), this simplifies to:
\[ \Delta G = \Delta G° \]

5. **Conclusion**:
Therefore, when \( Q = 1 \), it follows that \( \Delta G = \Delta G° \). This indicates that the system is at equilibrium, and there is no net change in the concentrations of reactants and products.

6. **Correct Option**:
Based on the analysis, the correct answer to the question is that when \( Q = 1 \), it implies \( \Delta G = \Delta G° \).