An electrical heater delivers three identical 25.0 kJ pulses of energy to 120 g of…
PHYSICS · Single correct · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
An electrical heater delivers three identical 25.0 kJ pulses of energy to 120 g of liquid ethanol that is already at its normal boiling point. Only 45 % of the electrical energy is absorbed by the ethanol; the rest is lost to the surroundings. The molar enthalpy of vaporization of ethanol is 38.6 kJ mol⁻¹ (molar mass = 46.1 g mol⁻¹). After the three pulses, what mass of ethanol remains in the liquid phase?
(a) 71g
(b) 40g
(c) 80g
(d) 95g