Textbook Problem 4.1

[nicole_ershaghi 3F]

Can someone assist with: How much heat is required to convert a block of ice of mass 42.30 g at -5.042 C into water vapor at 150.35 C? Are we supposed to know the enthalpy of fusion for water and the heat capacity of H2o (s) for this or will we be provided it?

[Soomin Son 2K]

Hi. For this problem, there are five steps which are: 1) Raising the temperature of the ice from -5.042C to 0.00C, 2) Melting the ice at 0.00C, 3) Raising the temperature of liquid water from 0.00C to 100.00C, 4) Vaporizing the water at 100.00C, and 5) Raising the temperature of the water vapor from 100.00C to 150.35C. For steps 1,3, and 4, you are using delta H=mCsdeltaT and for steps 2 and 4, you are using delta H=ndeltaH(fus). Then, to find the total heat required, you just need to add the heat obtained from step 1 to 5. The enthalpy of fusion for water and the heat capacity of H2o (s) is given on the constants and equations sheet.

[Soomin Son 2K]

Hi. For this problem, there are five steps which are: 1) Raising the temperature of the ice from -5.042C to 0.00C, 2) Melting the ice at 0.00C, 3) Raising the temperature of liquid water from 0.00C to 100.00C, 4) Vaporizing the water at 100.00C, and 5) Raising the temperature of the water vapor from 100.00C to 150.35C. For steps 1,3, and 4, you are using delta H=mCsdeltaT and for steps 2 and 4, you are using delta H=ndeltaH(fus). Then, to find the total heat required, you just need to add the heat obtained from step 1 to 5. The enthalpy of fusion for water and the heat capacity of H2o (s) is given on the constants and equations sheet.