carbon

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RenuChepuru1L
Posts: 58
Joined: Thu Jul 27, 2017 3:00 am

carbon

Postby RenuChepuru1L » Sat Mar 17, 2018 9:13 pm

when would you have to atomize or sublimize carbon. lets say you had 3c(gr)+4H2(g)->C3H8(g) and I was trying to calculate enthalpy of formation- do I have to sublimize carbon? I'm confused as to when all the elements need to be in gas form vs their most stable state.

Alyssa Parry Disc 1H
Posts: 53
Joined: Sat Jul 22, 2017 3:01 am

Re: carbon

Postby Alyssa Parry Disc 1H » Sat Mar 17, 2018 9:15 pm

I think that you only have to sublimize when you have only two molecules in different states and nothing else

Michaela Capps 1l
Posts: 50
Joined: Thu Jul 27, 2017 3:00 am

Re: carbon

Postby Michaela Capps 1l » Sun Mar 18, 2018 1:40 pm

You have to sublimize Carbon to the gaseous state because deltaH has to have them all as gasses.

Nate O 2L
Posts: 15
Joined: Fri Sep 29, 2017 7:06 am

Re: carbon

Postby Nate O 2L » Sun Mar 18, 2018 3:07 pm

Michaela Capps 1l wrote:You have to sublimize Carbon to the gaseous state because deltaH has to have them all as gasses.

What does sublimize mean again?

Anika_Patel_1G
Posts: 32
Joined: Fri Sep 29, 2017 7:06 am

Re: carbon

Postby Anika_Patel_1G » Sun Mar 18, 2018 3:16 pm

You must take deltaH sublimation into account of Carbon when finding delta H when using bond enthalpies. This is because the bond enthalpies in the table are given for bonds in gas phase, but the reaction has carbon in solid form.


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