If 540.0 kJ of energy is required to convert 1.00 mol of liquid water to steam at 100 °C, the amount of heat energy, in kilojoule, required to convert 100 g of water at 20 °C to steam at 100 °C is A - VCE - SSCE Chemistry - Question 15 - 2012 - Paper 1

Given that 540.0 kJ of energy converts 1.00 mol of water to steam, the energy required for 5.55 mol can be found using:

$\text{Energy} = 5.55 \text{ mol} \times 540.0 \text{ kJ/mol} \approx 2997 \text{ kJ}$

This can be rounded to 3.00 × 10² kJ.

From the calculations above, the energy required to convert 100 g of water at 20 °C to steam at 100 °C is approximately 3.00 × 10² kJ, corresponding to option C.