Why a non- spontaneous reaction becomes spontaneous when coupled with a suitable spontaneous reaction ?

Explanation

To understand why a non-spontaneous reaction becomes spontaneous when coupled with a suitable spontaneous reaction, we can analyze the concept of Gibbs free energy (ΔG) and how it relates to spontaneity.

### Step-by-Step Solution:

1. **Define Spontaneity**: A reaction is considered spontaneous if it occurs without the need for external energy. This is determined by the sign of the Gibbs free energy change (ΔG) for the reaction. If ΔG is negative, the reaction is spontaneous; if ΔG is positive, the reaction is non-spontaneous.

2. **Identify the Reactions**: Let's consider a non-spontaneous reaction (Reaction 1) represented as:
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