I don't understand how to get the answer

Question

A quantity of steam (250 g) at 118°C is condensed, and the resulting water is frozen into ice at 0°C. How much heat was removed?



Answer 1

There are four processes happening here:

1) The steam's temperature is being reduced from 118º C to 100º C

Q = mCΔT with C being the specific heat of steam.

2) Then the steam condenses to liquid (water)

Q = mL_v L_v is the heat of vaporization. Needed for the phase change to water at 100º C

3) The water then has to reduce its temperature by 100º C.

Q = mCΔT with C being the specific heat of liquid water.

4) Finally, the phase change to ice at 0º C.

Q = mL_f L_f is the heat of fusion.

The mass is given. The values for the specific heats, and heats of vaporization/fusion can be looked up.

Add up all four "Q's" for your answer.

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