What is the major product formed when salicylaldehyde is reacted with $2$ equivalents of bromine in glacial acetic acid at $0^{\circ} C$?

Aldol condensation will not take place in

Arrange the following compounds in decreasing order of reactivity towards nucleophilic addition reaction:
$I: HCHO$
$II: CH_3CHO$
$III: CH_3COCH_3$
$IV: PhCOCH_3$

The major product of the following reaction is:

When liquid $A$ is treated with a freshly prepared ammoniacal silver nitrate solution,it gives a bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid $B$ also forms a white crystalline solid with sodium hydrogensulphite but it does not give a test with ammoniacal silver nitrate. Which of the two liquids is an aldehyde? Write the chemical equations of these reactions also.

The reaction of ethyl methyl ketone with $Cl_2$ / excess $OH^{-}$ gives the following major product: