Ice at –20
o
C is added to 50 g of water at 40
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C. When the temperature of the mixture reaches 0
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C, it is found that 20 g of ice is still unmelted. The amount of ice added to the water was close to (Specific heat of water = 4.2J/g/
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C Specific heat of Ice = 2.1J/g/
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C Heat of fusion of water at 0
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C= 334J/g)