Addressed to JC students (secondary students may not yet be
ready to understand this) :
O2- cannot exist in aqueous solution (it can exist as part of an
ionic precipitate within solution, but not as an aqueous ion),
since being a stronger Bronsted-Lowry base than OH-, will
instantaneously undergo hydrolysis to generate OH- ions as follows
:
O2- + H2O ---> 2OH-
The above concept (known as
the leveling effect : in aqueous solution, any base stronger
than OH- (eg. O2- ion) will be forced to undergo hydrolysis to
ultimately generate OH- as the strongest remaining basic
species in aqueous solution) is indeed the reason why
alkalinity is measured in terms of pOH- and pH+ (or simply, pOH and
pH), and not as anything else (eg. pO2-).
Addressed to StudentQns :
Why is it that you have engaged a personal private
tuition teacher for a good long time, and yet keep
incessantly asking conceptually confusing qns
here (that betray your
acute-and-simultaneously-chronic debilitating perpetual
confusion over matters of physics and chemistry).
I'm not criticizing or chastising you here, I'm merely
observing that it just doesn't make sense that you would continue
hiring a costly personal private tuition teacher all this
while, yet seem to have none of your own needs (pertaining to
intellectual curiosity and academic support) met by your
personal private tutor.
There are many students who cannot afford (financially or
otherwise) a personal, private tutition teacher for academic
support. Ideally, this forum is for to help such students (who are
without personal tuition teachers). Students who can afford
tuition, should address your questions to your tutor (afterall,
that's what you're paying him/her a lot of $$$ for, right?).
It's inefficient and a waste of time
(for all parties involved) to struggle to work
through such deep-seated confusion (as your questions clearly
reveal you have) through an online forum. If an online forum can
effectively and efficiently address such needs, there wouldn't
be a need for a personal private tutor, would there?
So here the tragic irony appears to be :
you're engaging desperately on both platforms
(online forum, and a costly private personal tutor), but you're
still awfully confused.