When 'A' salt solution is added carefully to a saturated solution of `Fe(II)` sulphate acidified with dilute `H_(2)SO_(4)` a brown ring is formed at the junction of two liquids. Salt 'A' may be:

When a solid KCI is added to a saturated solution of AgCI "in" H_(2)O ,

When concentrated sulphuric acid is added slowly to a solution of ferrous sulphate containing nitrate ion, a brown colour ring is formed. The compositionn of the ring is

An aqueous solution of salt gives salt precipitate with AgNO_(3) solution as well as with dilute H_(2)SO_(4) . It may be

A nitrite solution is added to a saturated solution of iron (II) acidified with dilute acetic acid or with dilute sulphuric acid. If any reactions occurs then write the name and chemical composition of the products formed. Also write the chemical equations involved.

When KHSO_(4) is added into a concentrated solution of H_(2)SO_(4) the acidity of the solution.

A nitrite solution is added to a saturated solution of iron (II) acidified with dilute acetic acid or with dilute sulphuric acid.If any reactions occurs then write the name and chemical composition of the product formed.Write also the chemical equations involved.

On treated with dilute H_(2)SO_(4) , a salt gives a gas whch turns lime water milky. The salt can be