If the pressure of `N_(2)//H_(2)` mixture in a closed vessel is 100 atmospheres and `20%` of the mixture then reacts the pressure at the same temperature would be .

Options

A. The same
B. 90 atmospheres
C. 110 atmospheres
D. 80 atmospheres

Explanation

To solve the problem, we need to analyze the reaction between nitrogen (N₂) and hydrogen (H₂) in a closed vessel and how the pressure changes when 20% of the mixture reacts.

### Step-by-Step Solution:

1. **Initial Conditions**:
- The initial pressure of the N₂/H₂ mixture is given as 100 atmospheres.
- Let's denote the total number of moles of the gas mixture initially as \( n_{initial} \).

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