`A` and `B` are two salts. A with dilute `HCl` and `B` with con. `H_(2)SO_(4)` react to give reddish brown vapours, hence `A` and `B` respectively are :

A and B are two salts. A with dilute HCl and A and B with conc. H_2SO_4 react to give reddish brown vapours, hence A and B respectively are:

KBr, on reaction with conc. H_(2)SO_(4) , gives reddish-brown gas :

A and B are two salts. A reacts both with dil H_2SO_4 and conc. H_2SO_4 to give reddish brown vapours. However, B reacts only with conc. H_2SO_4 to give similar vapours. Hence A and B are respectively

Salts which give brown vapours with conc. H_(2)SO_(4) may be

Some salts which give brown vapours with conc, H_(2)SO_(4) may be :

A salt, which on heating with conc. H_(2)SO_(4) gives violet vapour is