deltaH Units

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Clarisse Wikstrom 1H
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Joined: Fri Sep 29, 2017 7:05 am

deltaH Units

Postby Clarisse Wikstrom 1H » Wed Jan 24, 2018 6:50 pm

When putting our final answer, how do we know whether the units for deltaH are kJ or kJ/mol? I've seen both so I was wondering if we would get marked off on the test if we wrote the wrong one. Thanks!

Sophie Krylova 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:06 am

Re: deltaH Units

Postby Sophie Krylova 2J » Wed Jan 24, 2018 7:46 pm

Usually you would give the answer in the same units as the data given.

Deap Bhandal L1 S1J
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Re: deltaH Units

Postby Deap Bhandal L1 S1J » Wed Jan 24, 2018 7:48 pm

An example would be the delta H of a reaction is in kJ. However delta H formation could be written in kJ/mole of the product if we divide the original number by the molar coefficient of the product. The kJ/mole is specific for a substance and if you know the amount of moles of the substance you can convert between the two.

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Re: deltaH Units

Postby CalebBurns3L » Fri Jan 26, 2018 1:04 am

You have to write out the units for each step of the reaction so you know what units your final answer should be in.

Jimmy Zhang Dis 1K
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Re: deltaH Units

Postby Jimmy Zhang Dis 1K » Fri Jan 26, 2018 11:02 am

I believe that standard delta H and delta H of a reaction are in KJ while delta H of formation is in KJ/mol

Chris Lamb 1G
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Joined: Fri Jun 23, 2017 11:39 am

Re: deltaH Units

Postby Chris Lamb 1G » Fri Jan 26, 2018 1:02 pm

I was under the impression that when calculating the standard reaction enthalpy, we use kJ/mol. For just regular reaction enthalpy, I would put kJ. But I would like to know if that is true or not.

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