(a) What is the action of red litmus on (i) dry ammonia gas (ii) solution of ammonia gas in water ?
(b) State the observations you would make on adding ammonium hydroxide to aqueous solution of
(i) ferrous sulphate (ii) aluminium chloride.

Explanation

(a) (i) Red litmus has no action on dry ammonia gas because it does not release any hydroxyl ions `(OH)^(-)`
(ii) When passed through water, ammonia `(NH_(3))` is converted ammonium hydroxide `(MH_(4)OH).` It dissociates to give hydroxyle ions `(OH)^(-)` and the solution is basic in nature. Red litums acquires a blur coulur when dipped in this solution.
(b) (i) A green precipitate of ferrous hydroxide would be formed by double displacement reaction.
`FeSO_(4)(aq) +2NH_(4)PH (aq)to underset(("Green ppt.))(Fe(OH_(2))(s)+(NH_(4))_(2)SO_(4)(aq)`
(ii) A shite pecipitate of aluminium hydroxide will be formed by double displacement reacton.
`AlCl_(3)(aq)+3NH_(4)OH(aq)tounderset(("White ppt."))(Al(OH)+_(3))(s)+3NH_(4)Cl (aq)`