8.67

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Rucha Kulkarni 2A
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Joined: Fri Sep 29, 2017 7:05 am

8.67

Postby Rucha Kulkarni 2A » Sun Jan 21, 2018 7:30 pm

Where exactly is the enthalpy of sublimation value for carbon used in this question?

Vincent Chiang 1L
Posts: 54
Joined: Fri Sep 29, 2017 7:05 am

Re: 8.67

Postby Vincent Chiang 1L » Sun Jan 21, 2018 9:42 pm

If I'm understanding your question correctly, the value of the standard enthalpy of sublimation of carbon is, it's +717 kJ*mol^(-1), which was written in the question. If I didn't interpret your question correctly, can you clarify the question?

Michelle Dong 1F
Posts: 110
Joined: Fri Sep 29, 2017 7:04 am

Re: 8.67

Postby Michelle Dong 1F » Mon Jan 22, 2018 10:04 am

I'm pretty sure it's because when writing out the standard reaction equation for each of the compounds, carbon's standard state is C(gr) which is a solid, but in order to use bond enthalpies, carbon must be in a gaseous form, so the enthalpy of sublimation for carbon is to convert C(gr) -- solid -- into gas form.


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