pH question involving sig figures (1 Viewer)

[Mr_Kap]

Is pH questions always 2 sig figures, or is it the lowest amount of sig. figures in the question. so can someone please clarify?

 

[Queenroot]

Usually good to stick to the figures in the question.

If none then 2 decimal places.

 

[Drsoccerball]

You must always pick the lowest SF in the question and if there is not values given use the SF on the standard sheet given.

 

[someth1ng]

Usually lowest SF in the questions but generally, pH is given to 2dp.

 

[Fizzy_Cyst]

Is pH questions always 2 sig figures, or is it the lowest amount of sig. figures in the question. so can someone please clarify?

Number of sig figs in concentration of H+ = number of decimal places in pH

I.e., 5.5x10^-3mol L^-1 of H+ would be pH = 2.26

This is a special case which is common to logarithms

 

[Librah]

Number of sig figs in concentration of H+ = number of decimal places in pH

I.e., 5.5x10^-3mol L^-1 of H+ would be pH = 2.26

This is a special case which is common to logarithms

This is how it goes, since -log(5.5x10^-3)=-(log(5.5)+log(10^-3)). log(10^x) gives always gives an exact number if it's base 10, and you take log(5.5) to 2 s.f.

I've seen some of the exemplary responses on pH though, i don't think they're too fussy on this.