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1184. What volume of ether vapour weighs the same as (a) 1 litre of air, (6) 2 litres of chlorine, (c) 7 litres of carbon dioxide ?

1185. How is methylic ether prepared ? Compare its chemical and physical properties with those of ethylic ether.

1186. What is acetic ether? Give its formula and describe its preparation.

ALDEHYDES.

1187. How are the aldehydes related to the alcohols and the acids ? Give general methods for their preparation. What is the derivation of the name aldehyde ?

1188. What is the difference between an aldehyde and a ketone ? What is the action of nascent hydrogen on each?

1189. What occurs when a mixture of acetate and formate of potassium is distilled ? How does this reaction serve for preparing the homologues of the fatty acids ? Give an example and equations for all the reactions.

1190. How is ethyl aldehyde obtained pure? What is the action of ammonia and of alkaline bisulphites on aldehyde ?

1191. What is the action of aldehyde on silver oxide ? Give an equation.

1192. What is the percentage composition of aldehyde? Name other bodies which have the same empirical formula.

1193. What is chloral ? How is it prepared, and how is it related to aldehyde ?

MONOBASIC ACIDS.

1194. How does formic acid occur in nature? How may it be produced from inorganic materials? Give two methods.

1195. How is formic acid prepared in quantity and obtained anhydrous ?

1196. What occurs (a) when sodium formate is heated, (6) when a formate is heated with sulphuric acid, (c) when formic acid is heated with mercuric oxide, (d) when chlorine acts on formic acid, (e) when calcium formate is distilled ? Give equations for each reaction.

1197. How would you prepare ammonium formate? What occurs when it is heated ?

1198. What occurs when potassium hydrate acts on chloroform ? Give an equation.

1199. How are hydrocyanic and formic acids related to each other?

1200. How is pyroligneous acid prepared and purified ? By what other names is the substance known?

1201. How may acetic acid be obtained from ethyl alcohol? Give other ways for preparing the acid.

1202. Give different methods for preparing vinegar.

1203. What weight of acetic acid would be required to neutralize exactly 7.892 grammes of potassium carbonate ?

1204. How is potassium biacetate prepared, and what occurs when it is heated ? Give an example of a similar reaction with an inorganic salt.

1205. What is the action of chlorine and of phosphorus trichloride on acetic acid ? Give equations.

1206. Give the formulæ of the following bodies : (a) silver acetate, (6) ethyl acetate, (c) potassium mono-chloracetate, (d) lead acetate, (e) acetyl chloride, (f) acetic anhydride, (g) acetamide.

1207. You are provided with bromine, acetic acid, sulphuric acid, and potassium cyanide, how would you prepare cyanacetic acid ? Give its formula, and state how a dibasic organic acid may be obtained from it.

1208. How may propionic acid be prepared starting with acetic acid ?

1209. How is lactic acid related to (a) propionic acid, (6) malonic acid, (c) glycollic acid ?

1210. Give a short account of the isomers of lactic acid, and explain their constitution by graphic formulæ.

1211. Give several methods for preparing lactic acid, and state which method you would adopt for obtaining large quantities of it.

1212. How is benzoic acid prepared ? In what respects do its reactions and preparation resemble those of acetic acid ?

1213. What occurs when benzoic acid is heated with lime? Give an equation.

1214. What is naphthalene, and how may benzoic acid be obtained from it ?

1215. By what reactions are formic, acetic, lactic, and benzoic acids recognised ?

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