Why don't you have to convert pressure into concentration when doing lnQ?


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Skyllar Kuppinger 1F
Posts: 52
Joined: Thu Jul 25, 2019 12:16 am

Why don't you have to convert pressure into concentration when doing lnQ?

Postby Skyllar Kuppinger 1F » Sun Mar 01, 2020 6:22 pm

How can you have a Q value that contains both pressure and concentration?. I've been converting the pressures to concentrations this whole time Bc I thought you had to make it uniform , and didn't know why I was getting it wrong until someone sent me their solutions manual.
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Kaylee Sepulveda 4G
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Joined: Thu Jul 11, 2019 12:16 am

Re: Why don't you have to convert pressure into concentration when doing lnQ?

Postby Kaylee Sepulveda 4G » Sun Mar 01, 2020 6:39 pm

Unless it specifically asks for Qp or Qc, I don't think you need to convert anything. And typically you're going to be given partial pressures for gases and concentrations for aqueous solutions, which I believe was the case in the problem you provided as an example.

Anish Natarajan 4G
Posts: 51
Joined: Thu Jul 25, 2019 12:16 am

Re: Why don't you have to convert pressure into concentration when doing lnQ?

Postby Anish Natarajan 4G » Sun Mar 01, 2020 8:54 pm

I believe it was mentioned in our discussion section that the ratios are going to be the same (although I could be wrong on this)

Skyllar Kuppinger 1F
Posts: 52
Joined: Thu Jul 25, 2019 12:16 am

Re: Why don't you have to convert pressure into concentration when doing lnQ?

Postby Skyllar Kuppinger 1F » Sun Mar 01, 2020 11:33 pm

Kaylee Sepulveda 4G wrote:Unless it specifically asks for Qp or Qc, I don't think you need to convert anything. And typically you're going to be given partial pressures for gases and concentrations for aqueous solutions, which I believe was the case in the problem you provided as an example.


Right but you can convert partial pressure into concentration by using pv=nRT. But I guess you don't have to


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