1. Describe and explain the action of the following reagents on oxalic acid; viz., sulphuric acid, potassium permanganate in presence of dilute sulphuric acid, phosphorus pentachloride. (12) 2. How is sugar obtained from the sugar-cane and purified? What is molasses, and how may the cane-sugar it contains be separated? (12) 3. How is pure oleic acid obtained from olive oil? What is the constitution of oleic acid, and how may it be converted into stearic acid? (14) 4. Describe exactly how you would determine the percentages of carbon, hydrogen, and chlorine in chloroform. (12) 5. A ketoxime, on analysis, was found to possess the following composition: Carbon 55 2, Hydrogen 10 3, Nitrogen 16.1 per cent. What is the formula of this compound, and from what ketone is it derived? (12) 6. How are ethers obtained, and what are their general properties? Give, with a sketch and practical details, an account of the method by which common ether is prepared. (12) 7. Give a short account of the synthesis and properties of urea. How is pure urea obtained from urine? (12) 8. How is lactic acid made from common sugar, and under what conditions does it yield butyric acid? Give the structural formulæ of both. (12) 9. Starting with acetic acid, how would you prepare acetyl chloride, acetic anhydride, acetamide, ethyl acetate and acetonitrile? (12) 10. Give a short account of the preparation and properties of acrolein, allyl alcohol, and acrylic acid. What is the action of bromine and of reducing agents on these substances? (14) 11. How is tartaric acid obtained? What is the relationship of this acid to succinic acid? In what respect does synthetical tartaric acid differ from the natural acid? (12) 12. Define, with examples, an amine, amide, and amido acid, and describe the action of nitrous acid on each of these classes of compounds. (12) SUBJECT XI. ORGANIC CHEMISTRY. Stage 2 and Stage 3. Before commencing your work, you must carefully read the following instructions: You may take Stage 2, or Stage 3, but you must confine yourself to one of them. Put the number of the question before your answer. Whenever possible, you are to express the reactions by equations. You are to give such numerical details as will show the mode of calculation. The value attached to each question is indicated by a number placed at the end of the question, but a full and correct answer to an easy question will in all cases secure a larger number of marks than an incomplete or inexact answer to a more difficult one. You are to confine your answers strictly to the questions proposed. The time allowed for this paper is three hours. Stage 2. INSTRUCTIONS. Read the General Instructions on pages 3 and 4. 21. What constitutional differences are represented by the division of carbon compounds into fatty and aromatic? (20) 22. Write the usually accepted formula for benzene and a short summary of the facts on which it is based. Why cannot benzene be represented by the formula (24) 23. By what methods can o-, m-, and p- nitraniline be prepared? 24. Ilow is phenylhydrazine prepared? Describe its principal properties and its action on aldehydes and ketones. (24) 25. What is the difference between chlorotoluene and benzyl chloride? Describe the preparation of each and its characteristic reactions. (24) 26. Describe three distinct processes for the preparation of benzoic acid. By what properties and tests is this acid recognised? (24) 27. What is an ureïde? Describe the preparation and properties of two members of this group. (24) 28. Describe the preparation of quinone from aniline. On what grounds is it stated that this compound does not contain hydroxyl? (24) 29. Enumerate the methods by which optically active substances may be separated from their inactive compounds. How can racemic compounds be distinguished from mixtures? (24). 30. Explain the following expressions :-a-bromopropionic acid; y-bromobutyric acid; d-tartaric acid; cis-crotonic acid; A1:3 dihydrobenzene. (21) 31. What constitution is assigned to naphthalene? How would you prepare the naphthols and phthalic acid from naphthalene (28) 32. How is vanillin obtained from vanilla? How is this substance prepared synthetically on the large scale? constitution. Discuss its (28) Stage 3. INSTRUCTIONS. Read the General Instructions on pages 3 and 4. 41. Write an account of the use of sodium ethylate for synthetical purposes, giving examples. (50) 42. How is benzaldehyde made, and what is the action on it of the following reagents: Hydrocyanic acid, strong nitric acid, ammonia, phosphorus pentachloride ? (50) 43. Contrast the methods of preparation and properties of the fatty and aromatic diazo-compounds, and discuss their respective constitutional formula. (50) 44. How is picric acid made and on what experimental evidence has its constitution been determined? (50) 45. Explain the processes by which indigo has been obtained from o-nitrobenzaldehyde, o-nitrophenylacetylene, aniline, and o-nitrocinnamic acid. (50) 46. By what processes have derivatives of pyridine been obtained from citric acid, malic acid, and from aceto-acetic ester? (50) 47. Discuss the probable constitution of meconic acid. 48. Write a short account of Claisen's work on the hydroxymethylene compounds. (50) (50) SUBJECT XIp. PRACTICAL ORGANIC CHEMISTRY. Stage 1. WRITTEN EXAMINATION, Before commencing your work, you must The value attached to each question is indicated by a number placed at the end of the question. You are to confine your answers strictly to the questions proposed. The time allowed for this paper is one hour. 1. How would you prove the presence of nitrogen in ammonia, aniline, gluten? (3) 2. What experiments would you make in order to establish the purity of a sample of chloroform? (3) 3. Make a sketch of the apparatus you would use and the precautions you would observe in determining the melting point of an organic compound? (3) 4. A colourless volatile liquid is either an alcohol, a ketone, or an ester; how would you determine to which of these classes of compounds it belongs? (5) 5. Give a list of organic compounds you have made, and describe in detail the process adopted in one case. (5) SUBJECT XIp. PRACTICAL ORGANIC Stage 1. PRACTICAL EXAMINATION IN CHEMICAL ANALYSIS. INSTRUCTIONS. You must be careful to state in your answers the numbers on the bottles supplied to you. Two and a quarter hours are allowed for this part of the examination. A.-White Bottle.-Test the substance for nitrogen, and determine its melting point. B.-Blue Bottle.-Analyse the substance qualitatively. SUBJECT XIp. PRACTICAL ORGANIC Stage 2. WRITTEN EXAMINATION. Before commencing your work, you must The value attached to each question is indicated by a number placed at the end of the question. You are to confine your answers strictly to the questions proposed. The time allowed for this paper is one hour. |