ANALYTICAL CHEMISTRY I.

Courses E, F and G.

1. What are alloys? Given an alloy for analysis, how would you get it into solution? What bad effect would too much acid in the solution have on the analysis? How would you get rid of the excess of acid?

2. Why is ferrous sulphide used in the laboratory as a source of hydrogen sulphide, instead of using lead sulphide?

3. You are required to analyse a solution which you know to contain copper nitrate but which may also contain lead nitrate or cadmium nitrate, or both of these. How would you proceed?

4. Why does lead occur in both Group I and Group II?

5. What would be indicated by:

(1) A black residue after washing Group I chlorides with ammonia? Of what is the black residue composed?

(2) The copious evolution of heavy white fumes when evaporating the solution of Group II nitrates with sulphuric acid?

(3) A deep blue solution on making the solution of Group II sulphates alkaline with ammonia? What is the formula of the blue compound?

(4) An insoluble residue after boiling Group II B sulphides with concentrated hydrochloric acid? What further treatment would you give this residue in order to identify the substance composing it?

6. Why is aluminium hydroxide soluble in sodium hydroxide and not in ammonium hydroxide?

7. Write equations for the following:—

(1) The action of nitric acid on ferrous sulphate. (2) The action of dilute hydrochloric acid on potassium chromate.

(3) The action of aqua regia on arsenic pentasulphide. (4) The reaction between "magnesia mixture" and ammonium arsenate solution.

(5) The reaction between mercuric chloride solution and stannous chloride solution.

ANALYTICAL CHEMISTRY I AND GENERAL
CHEMISTRY II.

Courses A, B, C and D.

1. Give completely the chemistry of the treatment of a silicate (a) with sodium potassium carbonate, and (b) with hydrofluoric acid.

2. Give an outline synopsis of the analytical groups, naming each group reagent, and each compound precipitated in each group.

3. Given a solution containing only bismuth chloride, cadmium chloride, arsenic chloride and stannous chloride, how would you separate them each from the others, and how would you identify each metal? Your method is to contain no unnecessary procedures.

4. Give step by step the systematic analysis of Group III.

5. Give the chemistry of the metaphosphate bead tests for cobalt, and for silica.

6. What is meant by chemical equilibrium? Show how the idea of chemical equilibrium can be made use of in explaining the facts of any particular reaction you may choose.

7. State briefly but definitely,

(a) The facts upon which the electrolytic dissociation theory is based.

(b) The assumptions made by this theory.

(c) The use of this theory in analytical chemistry.

8. Write all equations needed for the following reactions: (1) Oxidation of hydrogen sulphide to sulphuric acid by means of nitric acid.

(2) The precipitation of nickelic hydroxide only, from a solution containing salts of both nickle and cobalt.

(3) The action of sodium peroxide on chromium hydroxide in the presence of water.

(4) The action of bismuth hydroxide on sodium stannite.