pH and van’t hoff


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Marsenne Cabral 1A
Posts: 59
Joined: Fri Sep 28, 2018 12:19 am

pH and van’t hoff

Postby Marsenne Cabral 1A » Sat Mar 09, 2019 5:14 pm

why would the neutral ph change from 7 in a chemical reaction and how is that possible?

Ashley Kim
Posts: 62
Joined: Fri Sep 28, 2018 12:19 am
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Re: pH and van’t hoff

Postby Ashley Kim » Sat Mar 09, 2019 5:47 pm

The neutral pH can change with temperature, because pH is not constant with temperature.

Kathryn Wilhem 1I
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Joined: Fri Sep 28, 2018 12:27 am

Re: pH and van’t hoff

Postby Kathryn Wilhem 1I » Sat Mar 09, 2019 6:14 pm

With a temperature change, the K changes, so then the pH would also change because the concentration of H+ changes.

Joonsoo Kim 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

Re: pH and van’t hoff

Postby Joonsoo Kim 4L » Thu Mar 14, 2019 11:11 pm

When temperature increases, the Kw increases as well, which causes the neutral [H+] to increase and neutral pH to decrease. On the flip side, when temperature decreases, the Kw and neutral [H+] decrease, so the neutral pH increases. Neutral pH of 7 is only true at 298K.

Yvonne Du
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Joined: Fri Sep 28, 2018 12:23 am

Re: pH and van’t hoff

Postby Yvonne Du » Thu Mar 14, 2019 11:17 pm

Joonsoo Kim 4L wrote:When temperature increases, the Kw increases as well, which causes the neutral [H+] to increase and neutral pH to decrease. On the flip side, when temperature decreases, the Kw and neutral [H+] decrease, so the neutral pH increases. Neutral pH of 7 is only true at 298K.

Thank you this is very helpful!

Jonathan Christie 1I
Posts: 32
Joined: Mon Apr 09, 2018 1:38 pm

Re: pH and van’t hoff

Postby Jonathan Christie 1I » Sat Mar 16, 2019 7:36 pm

Thank you, this was a big help in figuring out where I went wrong on the Vant Hoff problem on test 2

Roberto Gonzalez 1L
Posts: 39
Joined: Fri Sep 28, 2018 12:17 am

Re: pH and van’t hoff

Postby Roberto Gonzalez 1L » Sun Mar 17, 2019 5:42 pm

A neutral pH of 7 is only true for water at 25 degrees celsius. As the temperature changes, Kw changes and therefore as [h30+] is calculated by taking the square root of Kw, the neutral pH value will differ accordingly.


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