Question

(a) What is the action on litmus of: (i) Dry ammonia gas (ii) Solution of ammonia gas in water (b) State the observations you would make on adding ammonium hydroxide to aqueous solutions of: (i) Ferrous sulphate (ii) Aluminium chloride

Answer 1

: 1) a) No color change will occur when litmus paper comes in contact with dry litmus paper.
b) A base turns red litmus to blue.
Ammonia solution turns red litmus to blue
B(i)When ammonium hydroxide is added to ferrous sulphate solution dull green coloured precipitate of ferrous hydroxide is formed.
FeSO4 +  2 NH4OH
Ferrous sulphate + Ammonium hydroxise
Fe (OH)2 + (NH4)2 SO4
Ferrous hydroxide + Ammonium sulphate

b.Aluminium chloride. 
b) When ammonium hydroxide is added to aluminium chloride solution a white gelatinous precipitate of aluminium hydroxide is formed.
AlCl3 + 3 NH4OH
Aluminium hydroxide + Ammonium hydroxide
 Al (OH)3 + 3 NH4Cl
Aluminium hydroxide + Ammonium chloride

Answer 2

the dry ammonia gas will have no action on the litmus because the litmus only show colour due to
the presence of water


the solution of ammonia in water will turn it from red to blue because base turn red litmus blue