kJ v. kJ/mol

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Jacob Bershatski 4C
Posts: 30
Joined: Fri Sep 28, 2018 12:21 am

kJ v. kJ/mol

Postby Jacob Bershatski 4C » Sun Feb 03, 2019 1:49 am

I am a little confused when we should be calculating enthalpy in terms of kJ and kJ/mol. Can someone please explain?

Christina Chang 1C
Posts: 34
Joined: Thu May 10, 2018 3:00 am

Re: kJ v. kJ/mol

Postby Christina Chang 1C » Sun Feb 03, 2019 2:16 am

I'm not sure if this is correct but I think that you would use kJ/mol when it is for the individual molecules and just kJ if it is the total enthalpy for the equation. I hope this helped!

Tuong Nguyen 2I
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Joined: Fri Sep 28, 2018 12:26 am
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Re: kJ v. kJ/mol

Postby Tuong Nguyen 2I » Sun Feb 03, 2019 2:47 am

Yeah I believe that Christina is correct. The overall enthalpy of a chemical reaction should be measured in kJ while other enthalpies for specific chemical species should be measured in kJ/mol unless specified.

Posts: 57
Joined: Fri Sep 28, 2018 12:28 am

Re: kJ v. kJ/mol

Postby Timothy_Yueh_4L » Sun Feb 03, 2019 2:47 pm

When dealing with the singular unit kJ, we typically refer to the amount of energy that is involved in the system, whether it be the formation of products, reactants, or the total amount of energy that was released or absorbed based on the amount of substance in the reaction. On the other hand, kJ/mol refers to the amount of energy lost or gained for a particular compound per mole. For instance when delta H of formation of NO2 = 34kJ/mol means that its takes 34 kJ of energy to form 1 mole of NO2.

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