11. Liquid methane has a heat of vaporization of 122 calories per gram (cal/g). Compare the effectiveness of liquid methane and water for evaporative cooling.

Water is more effective for evaporative cooling than liquid methane since, it would result in a higher temperature drop for the same mass of liquid methane.

Explanation:

Since the heat of vaporization of water is 540 calories per gram and that of liquid methane is 122 calories per gram, for each gram of the water evaporated, 540 calories is lost while for each gram of liquid methane evaporated, 122 calories is lost.

Since a higher heat loss would result in a higher temperature drop, water is more effective for evaporative cooling than liquid methane since, it would result in a higher temperature drop for the same mass of liquid methane.