Analytical Chemistry

The common reagents that are used in analytical chemistry for identification of cations are:

• sodium hydroxide

• sodium chloride

• ammonium hydroxide

• sulphuric acid

The cation that does not form a precipitate with ammonium hydroxide but forms precipitate with sodium hydroxide.

• Al3+ ion

• Zn2+ ion

• Ca2+ ion

• Ag1+ ion

The salt that gives a pale green precipitate with sodium hydroxide solution and a white precipitate with barium chloride solution is

• Iron(III) sulphate

• Iron(III) chloride

• Iron(II) sulphate

• Iron(II) chloride

A chloride which forms a precipitate that is soluble in excess of ammonium.

• Calcium chloride

• Ferrous chloride

• Ferric chloride

• Copper chloride

A solution of this compound gives a reddish brown precipitate with sodium hydroxide

• Ammonium sulphate

• Ferrous sulphate

• Lead carbonate

• Ferric nitrate

A solution gives a chalky white precipitate with lead nitrate solution. The precipitate disappears when an excess of the solution is added. What is the nature of the solution?

• strong acid

• weak acid

• strong alkali

• weak alkali

What do you observe when excess caustic soda is added to zinc nitrate solution?

• blue precipitate

• white gelatinous precipitate

• green precipitate

• colourless solution

What reagent will you use to distinguish between zinc nitrate and lead nitrate?

• Ammonium oxide

• Ammonium

• Ammonium hydroxide

• none of the above

What do we observe when ammonium chloride is heated with sodium hydroxide?

• Ammonia gas is evolved

• hydrogen gas is evolved

• oxygen gas is evolved

• white precipitate

_________ and _________ salt dissolve in sodium hydroxide

• zinc, lead

• lead, copper

• sodium, lead

• sodium, zinc