Question

Calculate the amount of heat required to vaporise 90 g of water at 100 celcius

Answer 1

The enthalpy of vaporization of water is 2256.4J/g, meaning that 2256.4J of heat are required to convert 1g of water at 100C to steam at 100C.

In this case, we have 90g of water at 100C and we want to vaporize it to steam (also at 100C).

This requires ΔH = 2256.4(90) = 225,640J or 225.64kJ of heat energy.