To calculate the amount of heat required to vaporize 200 g of water at its boiling point, we need to use the formula:q = n * Hvapwhere q is the heat required, n is the number of moles of water, and Hvap is the enthalpy of vaporization.First, we need to find the number of moles of water n . The molar mass of water HO is 18.015 g/mol.n = mass / molar massn = 200 g / 18.015 g/moln 11.106 molesNow we can calculate the heat required q using the enthalpy of vaporization Hvap of water, which is 40.7 kJ/mol.q = n * Hvapq = 11.106 moles * 40.7 kJ/molq 452.1 kJTherefore, the amount of heat required to completely vaporize 200 g of water at its boiling point of 100C is approximately 452.1 kJ.