`50` volumes of hydrogen take `20 min` of diffuse out of a vessel. How long will `40` volumes of oxygen take to diffuse out from the same vessel under the same conditions?

Explanation

To solve the problem of how long it will take for 40 volumes of oxygen to diffuse out of a vessel, given that 50 volumes of hydrogen take 20 minutes to diffuse out, we can use Graham's law of effusion, which states that the rate of effusion (or diffusion) of a gas is inversely proportional to the square root of its molar mass.

### Step-by-Step Solution:

1. **Identify the Given Information:**
- Hydrogen (H₂) diffuses 50 volumes in 20 minutes.
- Oxygen (O₂) volumes to diffuse = 40 volumes.
- Molar mass of Hydrogen (H₂) = 2 g/mol.
...