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Sig Figs

Posted: Wed Jan 23, 2019 4:13 pm
by Dina Geotas 4A
What are the sig fig rules for calculating pH and pOH? thank you!

Re: Sig Figs

Posted: Wed Jan 23, 2019 4:18 pm
by Grace Kim 1J
When calculating pH and pOH, count the number of sig figs given in the concentration and the pH/pOH should have that number of sig figs after the decimal. For example, if the pH=-log(1.4x 10^-6) then pH = 5.85 (two sig figs in 1.4 x 10^-6 and two after the decimal in 5.85).

Hope this helped!

Re: Sig Figs

Posted: Wed Jan 23, 2019 4:20 pm
by Ian Marquez 2K
Like said above, sig figs are a little bit different when dealing with pH and pOH because of what the log function does. A good rule is to just count sig figs in pH and pOH as the figures after the decimal point. This means that a pH of 1.2 has only one sigfig and 1.23 would have two. This rule only applies to pH and pOH as well as any other times you would apply a log such as pKa and pKb.

Re: Sig Figs

Posted: Thu Jan 24, 2019 12:01 am
by Vanadium Wang 4H
When calculating pH and pOH, sig figs are calculated from the initial concentration and applied after the decimal of the pH/pOH