1) The heat of fusion for gold at 1,063°C is 66.6 kJ/kg and the specific heat of
ID: 1984142 • Letter: 1
Question
1) The heat of fusion for gold at 1,063°C is 66.6 kJ/kg and the specific heat of gold is 0.128 kJ/kg °C. What is the energy needed to melt 100 grams of gold starting at 0°C?A) 20.3 kJ
B) 17.8 kJ
C) 12.3 kJ
D) 9.50 kJ
E) 7.50 kJ
2) The specific of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0°C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100°C is 2,256 kJ/kg. What is the final equilibrium temperature when 5.00 grams of ice at -15.0°C is mixed with 40.0 grams of water at 75.0°C?
A) 30.1°C
B) 28.3°C
C) 20.9°C
D) 18.6°C
E) 16.1°C
Explanation / Answer
1. Energy needed = mc (T2-T1) + mL = 0.1 x 0.128 x (1063-0) + 0.1 x 66.6 = 20.2664 kJ = 20.3 kJ Option - A is correct !!
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