Question

1. Calculate the amount of heat required to evaporate 5.20g of liquid water

Answer 1

M(water) = 18 g/mol

n(water) $= \frac{18}{5.20} = 3.46 \;mol$

Table value of ΔH(vaporization) for water at 100 °C is 40.657 kJ /mol

We have 3.46 mol,

$Q = 3.46 \times 40.657 = 140.73 \;kJ$