Duplicate Question
The question on this page has been marked as a duplicate question.
Original Question
How much heat (in kJ) is evolved in converting 1.00 mol of steam at 130.0 C to ice at -50.0 C? The heat capacity of steam is 2....Asked by Caleb
How much heat is evolved in converting 1.00 mol of steam at 155.0 ∘C to ice at -45.0 ∘C? The heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C).
Answers
Answered by
DrBob222
Let's see if you can do this yourself.
heat at phase change is
q = mass x heat vaporization at boiling point or
q = mass x heat fusion at freezing point.
Between phases it is
q = mass x specific heat x (Tfinal-Tinitial).
Now you have steam at 155 so it must go "within the phase" to 100 so that is equation 3.
Then you change from steam vapor to steam liquid. That's a phase change at the boiling point. Use equation 1.
Then you change T from 100 to zero C. That's equation 3 again.
At zero it freezes so that's a phase change from liquid to solid and you use equation 2.
Then you go from zero with a solid to -45 with a solid. That's equation again.
Then add all of the q values together.
heat at phase change is
q = mass x heat vaporization at boiling point or
q = mass x heat fusion at freezing point.
Between phases it is
q = mass x specific heat x (Tfinal-Tinitial).
Now you have steam at 155 so it must go "within the phase" to 100 so that is equation 3.
Then you change from steam vapor to steam liquid. That's a phase change at the boiling point. Use equation 1.
Then you change T from 100 to zero C. That's equation 3 again.
At zero it freezes so that's a phase change from liquid to solid and you use equation 2.
Then you go from zero with a solid to -45 with a solid. That's equation again.
Then add all of the q values together.
Answered by
Caleb
I'm still not getting the correct answer.
Answered by
Caleb
I'm getting 5.65 kJ
Answered by
DrBob222
Post your work for each step and I'll check it.
Answered by
DrBob222
Check your arithmetic. I It looks like you have the right digits (close anyway) but off by a factor of 10. You don't show what you're using for delta H vap or delta H fusion. I used 18 g for a mole of H2O, 334J for delta H fusion and 2257J for heat vap and 4.18 for specific heat liquid water.
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.