How much total energy converts 1.00 mol of ice at 0 °C to steam at 100 °C? (ΔHfus = 6.01 kJ/mol; liquid water molar heat capacity = 75.3 J/(mol·°C); ΔHvap = 40.7 kJ/mol)

Core Concept

Three stages stack: melting costs 6.01 kJ/mol, warming the liquid from 0 °C to 100 °C costs 75.3 J/(mol·°C) × 100 °C = 7.53 kJ/mol, and vaporizing costs 40.7 kJ/mol. Summing gives 6.01 + 7.53 + 40.7 = 54.2 kJ. Every segment of the heating curve contributes, so omitting any stage underestimates the total energy demand.