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Topic: pH at higher temp  (Read 2779 times)

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Offline poca

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pH at higher temp
« on: October 23, 2011, 09:32:10 AM »
pH of .03M nitric acid at 50 celcius. also pOH

Does the temp make this problem change from just doing -log of.03 thanks
I know the Kw changes but still the OH- and H+ from water is very small.

Offline Borek

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Re: pH at higher temp
« Reply #1 on: October 23, 2011, 05:47:38 PM »
Unless you know how pKa for nitric acid depends on temperature, temperature doesn't matter when calculating pH. But it will be important for pOH.
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Offline poca

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Re: pH at higher temp
« Reply #2 on: October 23, 2011, 06:16:20 PM »
I don't know how it affects. I can't find an equation or descrption.

pH nitric acid -log .3 =  .52
Then is it Kw is 5.47x10^-10 so so pkw 9.26

then pOH 8.74?

I was talking to a friend and he was saying something about subtracting from a new nuetral?

Offline Borek

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Re: pH at higher temp
« Reply #3 on: October 24, 2011, 02:38:31 AM »
I don't know how it affects. I can't find an equation or descrption.

Don't worry about that then.

Quote
pH nitric acid -log .3 =  .52

0.3 or 0.03?

Quote
Then is it Kw is 5.47x10^-10 so so pkw 9.26

No, please compare http://www.chembuddy.com/?left=pH-calculation&right=water-ion-product

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then pOH 8.74?

Correct approach, but incorrect numbers.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline poca

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Re: pH at higher temp
« Reply #4 on: October 24, 2011, 11:42:20 AM »
ok thanks

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