Question

How much heat must be removed from 5.0g of water at 10°C to become ice at 0°C ?

Answer 1

a third as much as 15.0 g

Answer 2

10°c to 0°c
Ht=mLf+mc(Tf-Ti)
m=5.0g
Lf=80cal/g
c=1cal/g°C
Ht=5.0(80)+(5.0)(1)(0-10)
Ht=400-50
=350cal