[d.lam.86]

Hi, I have great difficulty understanding where to start and proceed with this question from my textbook. Please take a look:

11.39 Water at 0°C was placed in a dish inside a vessel maintained at low pressure by a vacuum pump. After a quantity of water had evaporated, the remainder froze. If 9.31 g of ice at 0°C was obtained, how much liquid water must have evaporated? The heat of fusion of water is 6.01 kJ/mol and its heat of vaporization is 44.9 kJ/mol at 0°C.

This is how I approached this question:

Given: H₂O_(l)  H₂O_(g) ;   :delta:H = 44.9 kJ/mol

H₂O_(l)  H₂O_(s) (9.31 g); :delta:H = -6.01 kJ/mol

Past this point, I am having difficulties determining how I can find either the water evaporated or the remainder of liquid water that was left. If you kindly suggest a solution, then that would be greatly appreciated. Thanks!

[Yggdrasil]

How much heat would need to be removed for 9.31g of water to freeze?  How much water would need to evaporate in order to remove that amount of heat?