Agricultural Education — Examination Papers, 1873. Ixxxvii 
EXAMINATION IN CHEMISTEY. 
Maximum Number of Marks, 200. Pass Number, ICQ. 
I. General CiTemistrt. 
Wednesday, April 23rd, from 10 a.m. till 1 p.m. 
1. Describe the elements bydrogen and nitrogen. State some of 
tbe substances in ■nbicb they occur in nature, and how they are com- 
bined in those substances. In what proportions by weight and by 
volume do they unite with each other '? By what characters may they 
be distinguished from other elements and compounds ? 
■ 2. Point out the essential characters in which chemical compounds 
differ from mechanical mixtures, and illustrate your reply by the case 
of atmospheric air and other examples. 
3. Describe methods of preparing common hydrochloric and phos- 
phoric acids, and explain the chemistry of the processes. 
4. If 100 measures of a solution of common salt require 34 measures 
of a solution of silver nitrate, containing one-tenth of a grain in each 
measure, for the complete precipitation of all the chlorine, find the 
quantity of salt in each measure of the solution. (N : 0 : CI : Na : 
Ag = 14 : 16 : 35-5 : 23 : 108). 
5. Explain what is meant by diffusion of gases, and the importance 
of this property of gases in respect to respiration. State the experi- 
mental law as to the rates of diffusion of gases into one another through 
porous divisions. What will be the relative rates of diffusion of 
H'N and CO' into 0 ? 
6. Describe a method of preparing caustic soda, and explain the 
chemistry of the process. State the re-actions of caustic soda with 
iron (ferric) chloride, copper sulphate, and ammonium nitrate re- 
spectively. How can caustic soda be distinguished from sodium 
carbonate ? 
7. A solution of ammonia being given, it is required to find the 
proportion of ammonia to water : explain how to do it. 
8. Explain the nature of the chemical changes which occur in the 
ordinary fermentation of beer and bread. State the circumstances 
necessary to the fermentation, and some of the means by which the 
progress of such fermentation may readily be stopped. 
9. State the chemical constitution of soaps. Explain why soap 
■«urdles in hard water. 
10. What are the elements of albumen ? In what sort of organised 
bodies and in what parts of them does albumen occur ? In what sub- 
stance does it dissolve, and by what means can it be precipitated ? 
How is it distinguished from gelatine ? 
VOL. IX. — s. s. h 
