Answer to Question #202044 in Inorganic Chemistry for Moitheri Malelu

Question

Calculate the total amount of energy (in kJ) necessary to raise the temperature of 2.00 L of ethanol (density = 0.7849 g/cm3) from 18 0C to its boiling point (78.3 0C) and then to fully vaporize the liquid. Assume that it is a closed system where no heat exchange with the surroundings take place.

(Given: Cethanol = 2.44 J/g·K; heat of vaporization of ethanol at 78.3 0C = 38.56 kJ/mol.)

Answer 1

2.44 × 0.7849 × (78.3-18)

2.44× 0.7849 × 60.3

78.3 - 38.56 = 39.74

2.44 × 0.7839 × 100.04

= 191.35 kJ