If in a reaction at constant temperature, `n_(1)` moles of the gaseous reactants change into`n_(2)` moles of gaseous products , the difference in the enthalpy change and internal energy change of the reaction will be equal to `"…............."`.

Explanation

To solve the question, we need to determine the difference between the enthalpy change (ΔH) and the internal energy change (ΔU) for a reaction where `n1` moles of gaseous reactants convert into `n2` moles of gaseous products at constant temperature.

### Step-by-step Solution:

1. **Understand the Reaction**: We have `n1` moles of gaseous reactants converting into `n2` moles of gaseous products. The change in the number of moles of gas (Δng) can be expressed as:
\[ \Delta n_g = n_2 - n_1 \]
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