(b) Add an equal volume of dilute sulphuric acid followed by a few drops of aqueous potassium manganate (VII). Leave the mixture to stand.
(c) Add 1 cm³ of dilute nitric acid followed by 10 drops of aqueous silver nitrate.
(d) Add 1 cm³ of dilute hydrochloric acid followed by 10 drops of aqueous barium chloride solution.
3. Make a solution of about half your sample of M in distilled water and test 2 cm³ portions as follows:
(a) Add aqueous sodium hydroxide until no further change is apparent. Warm the mixture gently.
(b) Add an equal volume of dilute sulphuric acid followed by a few drops of aqueous potassium manganate (VII). Leave the mixture the stand.
(c) Add 1 cm³ of dilute nitric acid followed by 10 drops of aqueous silver nitrate.
(d) Add 1 cm³ of dilute hydrochloric acid followed by 10 drops of aqueous barium chloride.
(e) Transfer the rest of the solution to a boiling tube; add sodium hydroxide solution in excess. Reduce the contents of the tube to 3 cm depth by discarding the excess then add hydrogen peroxide solution. Identify the gas evolved by a positive test.
4(a) Strongly heat a sample of L in a dry tube. Take care not to smell any gas evolved. Test the gas with paper soaked in acidified potassium chromate solution.
(b) Heat solid M in a dry tube. Test the gas evolved with blue litmus paper.
Solid L : FeSO4(NH4)2SO4 Iron (II) ammonium sulphate
Solid M : CoCl2.6H2O Hydrated Cobalt (II) chloride