Cambridge International A & AS Level Business Studies Syllabus code 9707 Centres and candidates may choose to: • Take all A and AS components at one exam session, leading to the full Advanced Level qualification (Papers 1, 2 and 3) or • Take the AS components (Papers 1 and 2) at one exam session and, having received the AS qualification, take the additional A2 component (Paper 3) at a later session, leading to the full Advanced Level qualification or • Take the AS components only (Papers 1 and 2) at one exam session, leading to the Advanced Subsidiary qualification.
On Page 3 of your Acids & Bases document, you give calculations to work out the pH if either the acid or the base is in excess. What do you do if neither are in excess and you want to work out the pH at the equivalence point? The first method ([H+] in excess) gives zero and the second method ([OH-] in excess) gives “negative infinity” (dividing by 0).
Furthermore, if the [OH-] is in excess but this excess is *extremely* small you will get a low or negative pH (ie. the solution would seem to be acidic even with [OH-] in excess). Is this correct? I would have thought that with an excess of [OH-] the pH should always be >7 (at room temperature of course), at least for strong acid/strong base.