Question

How much energy (in kJ) is released when 16.4 g of steam at 121.5 degrees C is condensed to give liquid water at 60.5 degrees C? The heat of vaporization of liquid water is 40.67 kJ/mol and the molar heat capacity is 75.3 J/(K*mol) for the liquid and 33.6 J?(K*mol) for the vapor.

Answer 1

q1 = energy released to convert steam atg 121.5 to steam at 100 C.
q1 = mass steam x specific heat steam x (100-121.5) = ?

q2 = energy released to condense steam at 100 to liquid water at 100 C.
q2 = mass steam x heat vaporization

q3 = energy released in cooling liquid water from 100 C to 60.5 C.
q3 = mass water x specific heat water x (60.4-100) = ?
Total energy released is q1 + q2 + q3.