Internal energy after evaporation?

AI Thread Summary
The discussion revolves around calculating the change in internal energy after vaporizing 2 grams of water, requiring 1664 calories for the process. The conversion of calories to joules is correctly attempted, resulting in approximately 6965.504 J. However, the user struggles with the subsequent calculation, indicating a misunderstanding of the relationship between heat, mass, and internal energy change. It is noted that the problem lacks sufficient information for a complete solution. Clarification on the missing details is sought to resolve the issue.
Rblswimmer456
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Homework Statement



Two grams of water are sealed in a rigid con-
tainer; then the water is vaporized by heating.
1664 cal of heat is needed for vaporization.
What is the change in internal energy of the
water?
Answer in units of J.

Homework Equations



1 kcal= 4,186 J

The Attempt at a Solution



seems simple because there are only 2 given variables, so I don't know what I am doing wrong. Here is what I tried...
I first changed 1664 cal to 1.664 kcal then times that by 4186 J to get 6965.504 J then I divided that by .002 kg (change 2 g to .002 kg) but that answer was incorrect.

Any help to point me in the right direction would be greatly appreicated :)
 
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This problem statement is under-specified. There is missing information.
 
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