Under what conditions is the heat of reaction equal to enthalpy change?

Explanation

To determine the conditions under which the heat of reaction is equal to the enthalpy change, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Enthalpy Change (ΔH)**: It is a measure of the total energy of a thermodynamic system, including internal energy and the energy required to make room for it by displacing its environment.
- **Heat of Reaction (Q)**: It is the heat absorbed or released during a chemical reaction.

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