What amount of heat is needed to transform 200 g of water taken at a temperature of 40 degrees

What amount of heat is needed to transform 200 g of water taken at a temperature of 40 degrees Celsius into centigrade steam? Disregard the energy losses for heating the ambient air.

Initial data: m (mass of water to be converted into steam) = 200 g (0.2 kg); t (initial water temperature) = 40 ºС; heat losses are not taken into account.

Constants: C (specific heat capacity of water) = 4200 J / (kg * K); L (specific heat of vaporization of water) = 2.3 * 10 ^ 6 J / kg; tpap (temperature of the beginning of water vaporization) = 100 ºС.

Heat for converting water into steam: Q = Q1 + Q2 = C * m * (tpar – t) + L * m.

Calculation: Q = 4200 * 0.2 * (100 – 40) + 2.3 * 106 * 0.2 = 510 400 J = 510.4 kJ.