Calculate the volume of ethane required to be burnt to convert 100 kg of water at `20^@C` to steam at `100^@C` , assuming that only 40% of heat is useful. Heat of combustion of ethane is 371 kcal `"mol"^(-1)` . (One mole of gas occupies 22.4 litres at S.T.P. and latent heat of water is `2.25 xx 10^6 J kg^(-1)` )

Explanation

To solve the problem of calculating the volume of ethane required to convert 100 kg of water at 20°C to steam at 100°C, we will follow these steps:

### Step 1: Calculate the heat required to raise the temperature of water from 20°C to 100°C.

The formula to calculate the heat required (Q) is:
\[ Q = m \cdot c \cdot \Delta T \]
where:
- \( m = 100 \, \text{kg} \) (mass of water)
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