## Sig Figs for pH/pOH

LBacker_2E
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### Sig Figs for pH/pOH

Is there a special way to calculate sig figs for pH and pOH? I feel like this might have been mentioned in class, but now I am getting confused if this is for my chem lab instead? Do you determine sig figs based off of the decimal places of the numbers you are given or vice versa?

asannajust_1J
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### Re: Sig Figs for pH/pOH

number of sig figs in a pH or pOH only count after the decimal. For pH=3.489, there would be three sig figs since there are 3 decimal place. If the question is only 1 sig fig then the pH can be reported to 1 decimal place. Hope this makes sense!

MAC 4G
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Joined: Wed Sep 18, 2019 12:16 am

### Re: Sig Figs for pH/pOH

Generally, you would use the smallest number of sig figs you were given in a problem. For example, if you used a ICE box to find that x is 4.22*10^-5, then you're pH or pOH should have 3 sig figs (2 numbers after the decimal) like 4.38.

EMurphy_2L
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### Re: Sig Figs for pH/pOH

the number of sig figs in the problem asked is the number of decimal places you include after taking a log (which applies to pH and pOH)

stephaniekim2K
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Joined: Fri Aug 09, 2019 12:16 am

### Re: Sig Figs for pH/pOH

The number of sig figs to the answer of a log is the amount of sig figs after the decimal of the number you took the log of.

Minh Ngo 4G
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Joined: Thu Jul 25, 2019 12:17 am

### Re: Sig Figs for pH/pOH

Basically the digit before the “.” doesn’t count as sig fig. For example, pH =3.98 only has 2 sig fig. You count after the decimal place. However, the concentration of OH or H3O follow the usual rule.

nicole-2B
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### Re: Sig Figs for pH/pOH

significant figures for pH/pOH only counts after the decimal.

Renee Grange 1I
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### Re: Sig Figs for pH/pOH

in pH/pOH the you only count sig figs after the decimal point.