If `200 mL " of " N_(2) " at " 25^(@)C` and a pressure of 250 mm are mixed with `350 mL " of " O_(2) " at " 25^(@)C` and a pressure of 300 mm so that, the volume of resulting mixture is `300 mL`, what would be the final pressure of the mixture at `25^(@)C`?

Explanation

To find the final pressure of the gas mixture, we can use the formula derived from the ideal gas law, which states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases when they are combined in a constant volume.

### Step-by-Step Solution:

1. **Identify the given values:**
- For Nitrogen (N₂):
- Volume (V₁) = 200 mL
- Pressure (P₁) = 250 mm
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