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Angel Ni 2K
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am


Postby Angel Ni 2K » Sat Jan 20, 2018 1:04 am

For homework problem 8.37b, we are asked to calculate the enthalpy of vaporization of ethanol (given that 21.2kJ vaporized 22.45 grams). The answer key gives the answer as 43.5kJ/mol, but would 0.944kJ/g also be correct? In other words, what units are we supposed to use for enthalpy of vaporization or does it not matter?

Sara Sasaki 1K
Posts: 48
Joined: Fri Sep 29, 2017 7:05 am

Re: 8.37

Postby Sara Sasaki 1K » Sat Jan 20, 2018 3:51 am

I don't think it really matters since it's the same quantity, but to be safe I would put it in the units given in the problem, which is moles for #37. Hopefully someone else can clarify as well!

Luke Bricca 1H
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am

Re: 8.37

Postby Luke Bricca 1H » Sat Jan 20, 2018 9:27 am

Both of your answers are right, and I'm sure on the test it'll specify which units we're supposed to use. Usually enthalpy is given in kJ/mol, but not always.

Lily Sperling 1E
Posts: 49
Joined: Tue Oct 10, 2017 7:14 am

Re: 8.37

Postby Lily Sperling 1E » Sat Jan 20, 2018 9:43 am

Unless the question specifies desired units, my TA said that either answer would be acceptable.

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