8.0 moles of `SO_2` and 4.0 moles of `O_2` are mixed in a closed vessel. The reaction proceeds at constant temperature. By the moment equilibrium sets in, 80% of the initial amount of `SO_2` enters the reaction. Determine the pressure of the gas mixture in equilibrium if the initial pressure was 2.96 atm.

Explanation

To solve the problem, we need to follow these steps:

### Step 1: Write the balanced chemical equation
The reaction between sulfur dioxide (SO₂) and oxygen (O₂) to form sulfur trioxide (SO₃) can be represented as:
\[ 2 \, \text{SO}_2 + \text{O}_2 \rightarrow 2 \, \text{SO}_3 \]

### Step 2: Determine the initial moles of each reactant
From the problem, we have:
...