Jan. 8, 1885] 



NA TURE 



5. Give eq h ids here in I 

 obtaining hydn 



6. Explain fully in detail the methods of chemical calculation, 

 tin I make the pupils thoroughly understand the methods of cal- 

 culating quantities 



7. 1 'cmonstrate the physical properties of hydrogen, especially 

 its lightness and diffusibility. 



8. Compare the heating powei • of jet of hydrogen burning in 

 air and in oxygen. Explain the difference. 



9. 1 (escribe and (if possible) demonstrate the construction and 

 use of the oxy-hydrogsn blowpipe. 



10. Explain what is meant by heat of combustion, and define 

 the term "heat-unit." Show for this purpose side by side iS 

 gramme, of water and the quantity of water which would be 

 raised 1° C. in temperature by the heat developed in the forma- 

 tion of this quantity of water from its element-. 



11. Point out that hydrogen is a powerful reducing agent. 

 illustrating this by the reduction of oxide of iron. 



12. Show that nascent hydroge.i, or hydrogen at the moment 



ration from its compounds, frequently produces effects 

 that hydrogen in the free state does not. Bubble hydrogen 

 through ferric chloride solution and show that no discolorisation 

 take- place. Place it in contact with zinc and dilute sulphuric 

 acid and the c dour disappears. 



13. Explain the term nascent as applied to hydrogen and 

 other gas at the moment of its liberation from one of its com- 

 pounds, and distinguish between the atom of nascent hydrogen 



nd I 1 ile of bee hydrogen. 



IX. — Hydrochloric Acid and Chlorine 



1. Explain with equation and show the action of sulphuric 



anion salt. Collect the escaping gas by downward 

 I pi ement and show its solubility in water. 



2. Hold piece of paper dipped in ammonia solution in the gas. 



3. Saturate water with the gas, noting that its volume increases 

 and that considerable heat is developed. 



4 Exhibit 'the effects produced by adding the solution to 

 litmus and to silver nitrate solution. 



5. Show that it has no action on indigo, or on a mixture of 

 potassium iodide and starch solution. 



6. Pass the gas over red-hot iron and show the production of 

 hydrogen. 



7. Chlorine. — Heat oxide of manganese with the solution of 

 hydrochloric acid obtained in experiment 3, and collect several 

 jars of the escaping chlorine by downward displacement. Give 

 the equation. 



■omc of the gas into water. Exhibit the yellow colour 

 of the solution and show that it precipitates silver nitrate and 

 bleaches litmus and indigo. 



9. Burn a jet of hydrogen in chlorine. Show the disappear- 

 ance of the yellow-coloured gas. 



10. Moisten some paper with a few drops of turpentine and 

 throw it into a jar of chlorine. Point out the formation of 

 hydrochloric acid and the deposition of carbon. 



11. Explode a mixture of equal volumes of hydrogen and 

 chlorine. 



12. Point out how these experiments show that the gas pro- 

 duced in experiment 1 is a compound of chlorine and hydrogen. 

 Give the symbol and atomic weight of chlorine, and state the 

 composition of hydrochloric acid gas by weight and volume. 



13. Explain the production of chlorine from common salt, 

 sulphuric acid, and manganese dioxide. Give equ.1ii.1n-, and 

 instruct the students in the calculations of quantities. 



14. Show the combustion in chlorine, of phosph >rus, anti- 

 mony, and copper, and demonstrate its power to displace 

 bromine and iodine from their compounds with metals. 



15. Elei 1 ochloric acid solution, and explain the 

 fact of the evolution of equal volumes of its constituent gases. 



16. Explain the bleaching action of chlorine as being due to 

 the readiness with which it combines with hydrogen a 



thus acts as an oxidising agent. In illustration of this, show 

 that a piece of dry turkey red cloth when placed in dry chlorine 

 is not bleached. 



X. — Nitrogen and Ammonia 



1. The production of nitrogen from the air and the examina- 

 tion of its properties may here be repeated. 



2. Describe and (if possible) demonstrate the production of 

 ammonia by passing sparks from an induction coil or electric 

 machine through a mixture of nitrogen and hydrogen. Explain 

 that the reaction is not complete unless the ammonia is with- 



drawn .1- it is formed, owing to the fact that ammonia is readily 

 decomposed by heat. 



3. Prepare ammonia by heating an ammoniacal salt with 

 slaked lime. Collect by upward displacement and over mercury, 

 and show extreme solubility in water. 



4. Demonstrate and explain its combination with hydrochloric 

 acid, and show the volatility of sal ammoniac. 



5. Show that the aqueous solution of ammonia behaves in the 

 same way as a solution of sodium hydroxide, turning red litmus 

 blue, neutralising acids, and forming precipitates in solutions of 

 metals (copper, iron, and zinc salts, for example) of the same 

 composition as those produced by sodium hydroxide. Explain 

 that on this account it is considered that the ammonia solution 

 contains ammonium hydroxide. 



6. Pass dry ammonia gas over red-hot copper oxide and show 

 the production of water and metallic copper. 



7. Pass air and ammonia gas simultaneously over red-hot 

 copper as a method of preparing nitrogen. 



XT.— Ni'ric Acidandthe Oxida cf Nitrogen 



1. Explain on the blackboard the composition by weight of 

 the five distinct oxides of nitrogen as illustrative of the law of 

 chemical combination in multiple proportions, and as a deduc- 

 tion from this, explain Dalton's atomic theory and state clearly 

 what is meant by an atom. Demonstrate with a series of 

 blocks labelled with the symbols of the different elements how 

 this explains the observed facts of combination in multiple 

 proportions. 



2. Make clear to the student the difference between atom and 

 molecule, and explain atomic weight and molecular weight of 

 (1) hydrogen ; (2) oxygen, ozone ; (3) chlorine ; and then of 

 compounds such as (4) hydrochloric acid; (5) water; (6) 

 ammonia. 



3. De-cribe and (if possible) demonstrate the formation of 

 the red fumes of nitric peroxide on passing an electric spark 

 through air. 



4. Preparation of nitric acid from nitre and sulphuric acid. 

 Explain the reaction by an equation. 



5. Calculation of quantities to be carefully gone into. 



6. Exhibit nitre, nitrate of soda, sulphate and bisulphate of 

 potash, and sulphate and bisulphate of soda. 



7. Show the oxidising action of nitric acid by dropping it on 

 to some red-hot charcoal. 



8. Oxidising action of nitric acid on metallic tin and metallic 

 copper. 



8a. Deflagrate mixture of nitre and charcoal. 



9. Show the decomposition of nitric acid when heated by 

 dropping it into the bowl of a clay tobacco pipe, the stem of 

 which is etrongly heated, collecting the gas over water and 

 testing with a flaming splinter of wood. 



10. Heat potassium nitrate and collect the gas (O). 



11. Prepare nitric oxide from residue in experiment 10 by 

 treating with dilute sulphuric acid. Explain decomposition o 

 nitrous acid into nitric oxide and nitric acid. 



12. Prepare nitric oxide by action of nitric acid on copper 

 turnings. Collect the gas. Explain the reaction. 



13. Exhibit the direct combination of nitric oxide with oxygen. 

 Note the formation of red fumes of nitrogen peroxide and their 

 immediate absorption by water. 



14. Show that flame of a taper is extinguished in nitric oxide, 

 and that feebly burning phosphorus is also extinguished, but that 

 brightly burning phosphorus continues to burn, and with greater 

 brilliance than in ordinary air. Explain this. 



15. Preparation of nitrous oxide. Neutralise nitric acid with 

 ammonia. Evaporate the solution and obtain the solid salt. 

 Show the preparation of nitrous oxide with this residue. Collect 

 the gas over warm water. Give equation. Explain that nitrous 

 oxide is readily soluble in cold water. 



16. Show that like oxygen, nitrous oxide supports the com- 

 bustion of a taper, and explain that this is caused by the decom- 

 position of the gas, and the union of the constituents of the 

 taper with the oxygen of the nitrous oxide, and liberation of the 

 nitrogen. 



17. Also show that phosphorus and strongly ignited sulphur 

 burn in the gas, but that feebly ignited sulphur is extinguished. 

 Explain this. 



18. Point out the distinction between nitrous oxide and 

 oxygen : (1) the solubility of nitrous oxide in cold water, (2) the 

 production of nitrogen when bodies burn in it, (3) the fact that 

 nitric oxide does not produce with it red fumes, as is the case 

 with oxygen. 



