What amount of heat is needed to turn 20 g of ether into vapor taken at a temperature of 15 degrees Celsius.

The required amount of heat for heating and vaporization of ether: Q = Q1 (heating of ether) + Q2 (transition of ether to steam) = C * m * (tp – t) + L * m = (C * (tp – t) + L) * m, where С is the specific heat of the ether (2350 J / (kg * K)), tpap is the temperature of the beginning of vaporization of the ether (35 ºС), t is the initial temperature of the ether (15 ºС); L is the specific heat of vaporization of the ether (0.4 * 10 ^ 6 J / kg), m is the mass of the ether taken (20 g = 0.02 kg).
Calculation: Q = (2350 * (35 – 15) + 0.4 * 10 ^ 6) * 0.02 = 8940 J.