[Boxxxed]

Ice at 0.0 °C is used to cool water. What is the minimum mass of ice required to cool 325 g of water from 30.5 °C to 4.0 °C? (Heat of fusion = 333 J/g; CP values: ice = 2.06 J/g⋅K, liquid water = 4.184 J/g⋅K)

a. 103 g
b. 125 g
c. 325 g
d. 605 g
e. 1.75 × 10^4 g

q=325 x 4.18 x -26.5

Water must lose -36 KJ.

Ice must absorb +36 KJ

Temperature of ice = 0.0 C, final temp = 4.0C

How do I take the heat of fusion into account?

[Boxxxed]

Assuming the mass of ice is 103g..


melting of ice = 103*333 = 34299 J

q water from ice=103*4.18*4 = 1722 J

total 36021 J. Is this right? if so how do I calculate it without trial and error. And what do I need the specific heat of ice for?

[Borek]

When ice melts it absorbs the heat, just without changing temperature.

Try to express the process in a symbolic way (at least using symbol for unknown mass of ice), then solve for it. Simple algebra.