How is the presence of `SO_2` detected ?

Amount of oxalic acid present in a solution can be determined by its titration with KMnO_4 solution in the presence of H_2SO_4 . The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl

What happens when ethyne is treated with water in the presence of H_2SO_4 and HgSO_4 at 333-348K?

How phenol reacts with phthalic anhydride in the presence of concentrated sulphuric acid ?

How does chlorobenzene react with sodium in the presence of ether ? What is the name of rection ?

Write the chemical equations for the following reaction in each case. Ethanol is a warmed with ethanoic acid to form ethyl acetate in the presence of concentrated H_2SO_4