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FACULTY OF ARTS (HONOURS) AND FACULTY OF PRACTICAL SCIENCE (COURses b, d).

INDUSTRIAL CHEMISTRY I.

(Seven questions to be attempted).

1. Describe the manufacture of coal or semi-water gas; or the manufacture of acetic acid and acetone from grey calcium acetate.

2. How is calcium carbide manufactured ?

3. What two main processes are there for the fixation of atmospheric nitrogen? What are cyanamide, nitro

lime, 'Norway' saltpetre. and 'Chile' saltpetre?

4. Describe the process of making nitro-glycerine. Nitro-glycerine is used as an ingredient in what explosives? (Mention two.) Describe the composition of these.

5. How is nitric acid manufactured? What amount of sodium nitrate, 96% pure, and containing 1% of chloride, rest water, is required to produce 1 ton of 96%% nitric acid? How much sulphuric acid of 98% is needed? What percentage of nitrous acid might you expect in the finished product?

6. Give methods for the manufacture of caustic soda. 7. Describe the manufacture of carbon bisulphide, potassium ferrocyanide, potassium ferricyanide, Acheson graphite, oil dag. (Any two.)

8. What means are employed for the economical evaporation of solutions?

9. Show how to analyze a gas containing nitrogen, carbon monoxide, oxygen and hydrogen.

10. Describe the manufacture of a blue pigment and of a white pigment not containing lead.

FACULTY OF ARTS (HONOURS) AND FACULTY OF PRAC(COURSES B, C, D).

TICAL SCIENCE.

PHYSICAL CHEMISTRY II.

(Seven questions to be attempted, two of which must be selected from the first three.)

1. Describe in detail the calibration of a burette by means of an 'Ostwold pipette' of approximately 2 c.c. capacity, discussing all corrections which have to be applied. Show to what accuracy all the readings and calculations should be carried. What is the maximum accuracy of a titration performed with a burette holding 25 c.c. graduated directly into one-tenth c.c.? With what accuracy would you prepare a normal solution of Na, CO from the anhydrous salt, supposing it to be standardised against 0.8106 grams of pure phosphoric acid?

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2. Show how to determine the transition point of sodium sulphate. Explain why the transition points obtained from the heating and cooling curves are not identical. What corrections have to be applied, and how might impurities affect the transition? Explain the meaning of any sudden and sharp rise in the cooling curve. What other possible quadruple points are there in the system sodium sulphate and water?

3. How would you measure the velocity of hydrolysis of methyl acetate by an acid? Show how to interpret the results?

4. Define gram, litre, concentration, dilution, erg, cryohydrate, eutectic alloy, vapour pressure, supercooling. Change a pressure of 0.76 metres of mercury into kilograms per square centrimeter.

5. Derive the gas equation PV=RT, assuming Boyle's and Charles' laws. Express R in two different units, and explain its meaning.

6. Explain and illustrate the phase rule by taking sulphur as an example. How many phases can coexist in a system consisting of one component only?

Ammonium nitrate exists in three modifications. a rhombic, transition point to ẞ rhombic at 34°, ẞ rhombic transition point to y regular at 84°, y regular melts at 125°. the phase rule diagram.

Sketch

7. Apply the phase rule to (a) the constant boiling mixture of nitric acid and water (b. p. 126°, containing 69% HNO3), and show what happens if richer or weaker mixtures are distilled. (b) the distillation of a mixture of water and ether, two layers being originally present. (c) the formation of an eutectic alloy.

8. Fully explain the critical phenomena for a gas. What use is made of this in the liquefaction of hydrogen?

9. What is osmotic pressure, how is it measured, and prove in what way it depends on the nature of the semi-permeable membrane? Prove the connection between vapour pressure and osmotic pressure, explaining all symbols and defining all quantities.

10. Give illustrations showing how the discovery of new elements has always depended on the development of new or more refined physical chemical methods of investigation. What are the present methods for definitely fixing the atomic weight of an element?

11. Deduce the law of mass action and apply it either to the equilibrium between a weak acid in aqueous solution, and the ions formed by its dissociation, or to the equilibrium between sodium carbonate and barium sulphate in a fusion. What is Ostwald's dilution formula?

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