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Class D. —Chemistry (Optional) Time allowed Three hours 1. Write down the names and symbols of all tho known oxides of the following elements H, N, P, S, C, Si. 2. Express 100° F in terms of degrees Centigrade, and 200° C. in terms of degrees Fahrenheit. 3. Write down equations to show how the following gases are made 0, H, CI, C 0.,, S0 2 , CO, H a S. 4. How would you explain to a class the difference between a chemical compound and a mixture ? 5. Explain how you would show the properties of the following gases O, 11, CI, C0 2 , N, NH 3 . 6. What weight of hydrogen is liberated by the action of 100 grammes of sodium on water? (Na = 23.) 7 How much oxygen by weight is got by heating 100 grammes of chlorate of potassium ? (X = 39.) 8. Explain fully how sulphuric acid is made. 9. Explain how either ammonia or bleaching powder is made. 10. State what you know about either ozone or the diamond. 11. What is the chemical action of chlorine as a bleacher and disinfectant? 12. In what ways do plants and animals affect the atmosphere ?

Class D.—Electricity (Optional) Time allowed- Three hours 1. Describe the details of construction and the properties of an electro-magnet. 2. How would you test the kind of electricity in a body, using for the purpose a gold-leaf electroscope ? 3. Describe and explain the action of any form of induction electric machine. 4. Describe the quadrant electrometer, and contrast the use of electroscopes that act by induction alone with those that have a constant charge. 5. Give a description of a lightning conductor, explain its action, and state the area it is supposed to protect. 6. What are the chemical changes of a Bunsen's battery ? Explain fully why it is so much more useful for experimental purposes than a copper and zinc one-fluid cell. 7. Give an account of experiments to illustrate the elementary principles of magneto-electric induction. 8. Describe any form of dynamo-electric machine used for generating electricity for ordinary electric light. 9. Make a sketch illustrating a Morse telegraph with relays. 10. Describe some form of apparatus for estimating temperature by means of electricity

Class D.—Sound and Light (Optional) Time allowed Three hours 1. What circumstances affect the velocity of sound in a body? How is the velocity of sound in a glass rod ascertained ? 2. Give an account of tho phenomena of resonance. What use is made of it in musical instruments ? 3. Describe how the character of a musical note has been determined, either by synthesis or analysis. 4. What are tho laws of the vibrations of strings ? Upon what does the character of the note of a string depend ? 5. What are the laws of reflection ? Draw a diagram to illustrate the formation of a virtual image in a convex mirror 6. Show by a diagram how an image is formed in a camera. 7 What is the difference between a beam of red polarized light and one of solar light ? 8. Describe the stereoscope. 9. Show how the image is produced by means of any form of telescope. 10. Describe a spectroscope, and state the kind of spectrum that is given by solar and by stellar light.

Class D.—Heat (Optional) Time allowed Three hours 1. How is the coefficient of absolute expansion of mercury determined? What is its value ? 2. Name the several methods of determining specific heat. Describe the method of mixtures in detail. 3. Describe the mode of determining the relative conductivity of liquids. Why does a liquid get hot more quickly when the heat is applied to the bottom than when it is applied to the top of the vessel ? 4. What are the laws of ebullition? Describe the phenomena of boiling water 5. Describe the formation of dew Upon what circumstances does its copious formation depend ?