Significant figures for pH (1 Viewer)

[hs17]

Are significant figures for pH different from how we normally calculate significant figures?

E.g. would pH of 5.22 be 2 significant figures instead of 3 (only counting figures after decimal point)?

 

[Sp3ctre]

Correct, sig figs work a bit differently for logs. For a log, the number of sig figs is based on its decimal component (i.e. 0.22).
Therefore, a pH of 5.22 would have 2 sig figs based on its decimal component.

Keep this in mind whenever you're calculating pH, same rule applies when finding [H+] too!

 

[hs17]

So, say the pH is 5.22 and I'm asked to calculate [H+]...would my answer be to 2 significant figures i.e. 6.0 x 10 ^-6 ?

 

[CM_Tutor]

So, say the pH is 5.22 and I'm asked to calculate [H+]...would my answer be to 2 significant figures i.e. 6.0 x 10 ^-6 ?

Yes. 2 dec pl in a pH means 2 sig fig in a concentration, and vv.