John has three bottle of mineral acid but does not know which is which since he did not label the bottles before filling them. Suggest a method to which could be used to identify the acids.

Answer 1

Do you have a list of the mineral acids? It would help since there are more than three in practice. The usual ones are HCl, H2SO4, HNO3 but there are many more.
You can read more about them here.
http://en.wikipedia.org/wiki/Mineral_acid

Here is a simple solubility chart which should help you identify them. For example, to test for sulfate (if H2SO4), add BaCl2 and a white ppt insoluble in HNO3 denotes H2SO4. AgNO3 gives a white ppt of AgCl with HCl. ETC.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html