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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Survivor on June 08, 2008, 02:31:10 pm

Title: How much pH stuff do we need to know?
Post by: Survivor on June 08, 2008, 02:31:10 pm
I've been doing practice exams and obviously, the course has changed a lot due to the absence of the equilibrium topic. I've been skipping the pH questions because my school hasn't really been focusing a lot on them and I thought it would fall under the equilibrium section. Before it's too late, to what extent of pH do we have to know? I don't want to be a fool and lose marks unnecessarily in the exam. Thanks.
Title: Re: How much pH stuff do we need to know?
Post by: Mao on June 08, 2008, 04:19:26 pm
[H+] * [OH-] = 10^-14

some of the formulas for standard acids and bases [and their relative strengths]
know what conjugates are, and the properties of conjugates of weak acids and bases [hence where equivalence points and end-points occur]
know what indicator is appropriate
standard titrations, titration curves, back titrations

and i think that's really it

[oh, and the common reactions, such as acid + metal carbonate -> salt + carbon dioxide + water]
Title: Re: How much pH stuff do we need to know?
Post by: bec on June 08, 2008, 04:28:21 pm
finding pH of diprotic acids?
Title: Re: How much pH stuff do we need to know?
Post by: orangez on June 08, 2008, 09:14:02 pm
Also, finding concentrations/how much of a substance you need to add via working out [H30+] (in the '07 VCAA MCQs).

As for finding pH of diprotic acids, all you need to know is that they form 2 hydronium ions, if it is an acid + water reaction. The rest is trivial.
Title: Re: How much pH stuff do we need to know?
Post by: shinny on June 08, 2008, 09:43:42 pm
as orangez said, the hardest pH stuff ull need to know is in the '07 VCAA mc..question 15 and 16. the majority of the state got these wrong, and theyre actually quite hard stoic questions so give them a go

theyre not in checkpoints (not sure why since we're actually able to do them - it doesnt involve equilibrium) so just go grab it off the vcaa site
Title: Re: How much pH stuff do we need to know?
Post by: Survivor on June 09, 2008, 09:03:18 am
Ah, thank you :D I will go look back at the VCAA '07 pH questions, I think I crossed them out last time I did the paper. Will go back to it.

A'ight, thanks for all the answers guys. pH of diprotic sounds managable XD Have fun studying.