A 1 L flask containing vapours of methyl alcohol (molar mass 32) at a pressure of 1atm and `25^@C` was evacuated till the fill was `10^(-3)` mm. How many molecules of methyl alcohol are left in the flask ?

Explanation

To solve the problem of how many molecules of methyl alcohol are left in a 1 L flask after evacuation, we will follow these steps:

### Step 1: Convert the pressure from mm Hg to atm
The pressure after evacuation is given as \(10^{-3}\) mm Hg. We need to convert this to atm using the conversion factor \(1 \text{ atm} = 760 \text{ mm Hg}\).

\[ P = \frac{10^{-3} \text{ mm Hg}}{760 \text{ mm Hg/atm}} = \frac{10^{-3}}{760} \text{ atm} \]
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