JUST NEED HELP ON PART B An ice-making machine inside a refrigerator operates in

Question

JUST NEED HELP ON PART B

An ice-making machine inside a refrigerator operates in a Carnot cycle. It takes heat from liquid water at 0.0C and rejects heat to a room at a temperature of 23.7 C. Suppose that liquid water with a mass of 77.7 kg at 0.0C is converted to ice at the same temperature.

Take the heat of fusion for water to be Lf = 3.34×105 J/kg .

Part A

How much heat |QH| is rejected to the room?

Express your answer in joules to four significant figures.

2.820×107

  J  

Part B

How much energy E must be supplied to the device?

Express your answer in joules.

2.820×107

  J  

Explanation / Answer

A)
|QH| = m*Lf
            = 77.7 * 3.34*10^5
            = 2.595*10^7 J

B)
use:
effeciency =Q/W = 1- (TL/TH)
Q/W = 1- (TL/TH)
2.595*10^7 /W = 1 - (273/ (23.7+273))
2.595*10^7 /W = 1 - 0.92012
W = 3.249*10^8 J
Answer: 3.249*10^8 J

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