How much energy does it take to convert 1.000 kg of steam at 300.0 oC ice at – 32.0 oC?
[Specific heat capacities: ice, 2.1 J/g· oC; liquid, 4.2 J/g· oC; steam, 2.0 J/g· oC; ? Hvap = 40.66 kJ/mol; ? Hfus = 6.01 kJ/mol]
Formulas:
q = mass x specific heat x change in temp
q = moles x Heat of phase change
This is my work, I don't know if it's right or not:
1kg x 103 = 1000g
? mol H2O = 1000g / 18.01528 = 55.40166 mol H2O
q= 1000g (2 J/g) 200 C = 400,000 J / 1000 = 400 kJ
q= 55.40166 mol H20 ( -40.66 kJ ) = -2252.631579 kJ
q= 1000g (4.2 J/g) 100 C = 420,000 J / 1000 = 420 kJ
q= 55.40166 mol H20 ( -6.01 kJ) = -332.9639766 kJ
q= 1000g (2.1 J/g) 32 = 67200 / 1000 = 67.2 kJ
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-1698 kJ total energy
EDIT:
I found out what was wrong. I didn't calculate my temperatures correctly. I did initial - final instead of final - initial. My Final Answer: -3,471,200 J