The vapour pressure of water is `12.3 kPa` at `300 K`. Calculate vapour pressure of `1` molal solution of a solute in it.

Explanation

To solve the problem of calculating the vapor pressure of a 1 molal solution of a solute in water, we will follow these steps:

### Step 1: Understand the definition of a 1 molal solution
A 1 molal solution means that there is 1 mole of solute dissolved in 1 kg (1000 g) of solvent (in this case, water).

### Step 2: Calculate the number of moles of water
The molar mass of water (H₂O) is approximately 18 g/mol. To find the number of moles of water in 1000 g, we use the formula:

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