Physics-Phase change

Question

Calculate the quantity of heat needed to turn 230 gg of 100∘C∘C water to steam at the same temperature. The heat of vaporization for water Lv is 540 cal/gcal/g.

Answer 1

The heat goes only towards the phase change (liquid to vapor), since the initial water is already at the boiling temperature 100° and the steam will remain at the same temperature 100°.

Heat = mass x heat of vaporization = 230g x 540 cal/g = 124,200 calories.

Convert to Joules, if necessary. I hope this helps.