How to determine which has higher pH value among any 2 given solutions(preferably both acids or both bases)?

Question

for eg :- Which has higher pH value NaOH or NaHCO3? and why?

Answer 1

It depends on 2 things.
The concentration and stregnth of the acids /bases
In your example you are comparing a strong base (NaOH) with a weak base (NaHCO3), so for the same concentration of the two, NaOH will have a higher pH since it is stronger.
If both were weak you would need to know the Kb (or pKb values): the stonger base will be the one with higher Kb (or lower pKb) and will have a higher pH.

For acids, the weaker acid will have a higher pH

Answer 2

in case you dissolve a stable acid, this is going to dissociate thoroughly into H+ and the acid counter-ion. HCl, case in point, varieties H+ and Cl-. because of the fact HCl is a robust acid, Cl- won't %. up protons, so it is not elementary, and it may not donate protons, so it is not acidic, i.e. that's independent. CH3COOH (acetic acid) is a susceptible acid. this is going to not donate a proton, in different words, the acetate ion (CH3COO-) is extra probably to %. up a proton to variety the stable acid. for the reason that acetate possibilities up a proton, that's elementary. consequently, once you titrate a susceptible acid with a stable base, the tip factor is at a elementary pH (i.e. greater than 7). With a susceptible base and robust acid, this is any different way around. susceptible bases are unlikely to settle for protons, so their conjugate acids are extra probably to donate protons particularly. consequently, whilst titrating a susceptible base with a stable acid, the tip factor would be at an acidic pH (decrease than 7). desire that's clever.