Which quantity out of `Delta_(r)G` or `Delta_(r)G^(@)` will be zero at equilibrium?

Explanation

To determine which quantity, \( \Delta_r G \) or \( \Delta_r G^\circ \), will be zero at equilibrium, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gibbs Free Energy**:
- The Gibbs free energy change (\( \Delta_r G \)) for a reaction indicates the spontaneity of the reaction under non-standard conditions. It can be calculated using the equation:
\[
\Delta_r G = \Delta_r G^\circ + RT \ln Q
...