A `10.0 L` cylinder of oxygen at `4.0 atm` pressure and `17^(@)C` developed a leak. When the leak was repaired, `2.50 atm` of oxygen remained in the cylinder, still at `17^(@)C`. How many moles of gas escaped?

Explanation

To solve the problem of how many moles of oxygen gas escaped from the cylinder, we will follow these steps:

### Step 1: Identify the given values
- Initial pressure (P1) = 4.0 atm
- Final pressure (P2) = 2.5 atm
- Volume (V) = 10.0 L
- Temperature (T) = 17°C

...