Question

Problem 13:   Suppose you place 0.255 kg of 20.5°C water in a 0.45 kg aluminum pan with a temperature of 144.5°C, and 0.012 kg of the water evaporates immediately, leaving the remainder to come to a common temperature with the pan.

What would be the final temperature, in degrees Celsius, of the pan and water? The heat of vaporization of water is Lv = 2256 kJ/kg. You may neglect the effects of the surroundings and the heat required to raise the temperature of the vaporized water. Te =

Answer 1

I let final temperature: T Heat lost by aluminium Q = 0.45Smu (144.5-T) = 0.4500-9 (144:5-7)+103 .. 20.405 (144:5-7) 2103 J Heat gain by watch -0.012x 4.2% (100-2005) x163 +0.0124 2256103 + (0-255-0.012) x 4.2 (T-2015) XlO3 = 31078.8 + 1020.6(T-2015) dina Clout 405 (144.5-1) = 31078-8 +10 20.6 48366 = 1425-67 (T-2015) T= 33.93°c)