Sig Figs in pH

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Mizuno_Mikaela_1D
Posts: 29
Joined: Wed Sep 21, 2016 3:00 pm

Sig Figs in pH

Postby Mizuno_Mikaela_1D » Fri Dec 02, 2016 12:15 am

I recently went to a review session and the TA said that the number of sig figs in your pH number is counted after the decimal( so not including the number in the ones place). For example if the number with the lowest sig figs in your calculation has 2 sig figs and your pH calculated is 7.1345, you would write 7.13 instead of 7.1. However, in lecture, examples counted the number in the ones place so 7.1345 would be written as 7.1.

So I'm wondering are sig fig rules different for pH or not?

Sangita_Sub_3H
Posts: 23
Joined: Sat Jul 09, 2016 3:00 am

Re: Sig Figs in pH

Postby Sangita_Sub_3H » Fri Dec 02, 2016 6:39 am

I think when in doubt, it is always best to keep 3 sig figs, even for ph :)

Liam Giffin 2B
Posts: 34
Joined: Fri Jul 22, 2016 3:00 am
Been upvoted: 1 time

Re: Sig Figs in pH

Postby Liam Giffin 2B » Fri Dec 02, 2016 5:37 pm

I have a somewhat similar question. It appears in the solutions manual and previous finals solutions that in calculations involving a kpa of kpb that the sig figs of the kpa or kpb are ignored in the solution. Is this true?


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