For all UK students you should now use the New A-level guides below.
At the bottom of the page I have left the old syllabus notes as I think they are more useful for the international EDXCEL A-level Chemistry course. They were not written for the international course though.
New A-level 2015
The revision guides are in syllabus order. There are no modules.
12-acid-base-equilibria (updated February 2017)
Old Syllabus Revision Guides
Here are the Edexcel revision guides. Mod 1+ 2 are AS, Mod 4+ 5 A2.