1 Some chemical tests are described below. Warm with Fehling s (or enedict s) solution Warm with acidified potassium dichromate(vi) solution dd sodium carbonate solution dd 2,4-dinitrophenylhydrazine solution (a) Which test always gives a positive result with carbonyl compounds? (b) Which test would give a positive result with ethane-1,2-diol? (c) Which test would result in effervescence with ethanoic acid? (Total for Question = 3 marks) PhysicsndMathsTutor.com
2 The diagram below shows part of the mechanism for the nucleophilic addition of hydrogen cyanide to butanone. O H 3 H 2 H 3 Step 1 Intermediate X Step 2 N Organic Products (a) The formula of the intermediate X is ON + H 3 H 2 H 3 O H 3 N H 2 H 3 O H 3 N H 2 H 3 OH + H 3 N H 2 H 3 PhysicsndMathsTutor.com
(b) onsider the dissociation of the weak acid, HN. HN(aq) H + (aq) + N (aq) Which of the following reagents would shift the position of the equilibrium towards formation of the nucleophile, N? KOH KN H 2 SO 4 H 3 OOH (c) Which statement about the mixture of organic products formed is not correct? The mixture contains products with chiral molecules. The mixture rotates the plane of plane-polarized light. The mixture contains products with the nitrile functional group. The mixture contains products each of which has four carbon atoms in a straight chain. (Total for Question = 3 marks) PhysicsndMathsTutor.com
3 This question is about four organic compounds, each containing two carbon atoms.. H 3 H 2 OH H 3 HO H 3 OOH H 3 Ol (a) Which is oxidized by ammoniacal silver nitrate? (b) Which has the highest boiling temperature? (c) 0.01 mol of each compound is heated separately with excess acidified sodium dichromate(vi). Which compound reduces the largest amount of sodium dichromate(vi)? (d) 0.01 mol of each compound is added separately to identical volumes of water. Which solution would have the lowest ph? PhysicsndMathsTutor.com (Total for Question = 4 marks)
4 n organic compound reacts with both acidified potassium dichromate(vi) and lithium tetrahydridoaluminate (lithium aluminium hydride). The organic compound could be a primary alcohol. an aldehyde. a ketone. a carboxylic acid. (Total for Question = 1 mark) 5 Ketones react with both 2,4-dinitrophenylhydrazine solution and Tollens reagent. 2,4-dinitrophenylhydrazine solution but not with Tollens reagent. Tollens reagent but not with 2,4-dinitrophenylhydrazine solution. neither Tollens reagent nor 2,4-dinitrophenylhydrazine solution. (Total for Question = 1 mark) PhysicsndMathsTutor.com
6 solution of 2,4-dinitrophenylhydrazine (rady s reagent) is used as a test for organic functional groups. (a) The positive result of the test is the formation of a yellow solution. an orange precipitate. a red solution. a green precipitate. (b) Which of the following gives a positive result with a solution of 2,4-dinitrophenylhydrazine? Only aldehydes Only ketones Only aldehydes and ketones ny compound containing the O group (c) The initial attack by 2,4-dinitrophenylhydrazine, when it reacts, is by a free radical. an electrophile. a nucleophile. a negative ion. (d) The product of a positive test, a 2,4-dinitrophenylhydrazone, contains which of the following bonds? N N N O (Total for Question = 4 marks) PhysicsndMathsTutor.com
7 8 PhysicsndMathsTutor.com
9 This question is about the four organic substances shown below. H 3 H 2 H 2 H 2 HO H 3 H 2 H 2 H 2 OOH H 3 OH 2 H 2 H 3 H 3 H 2 H 2 H 2 Ol Which substance will (a) give a positive result with both rady s and Tollens reagents? (b) be formed by the oxidation of a secondary alcohol? 3 of water? (d) form steamy fumes in the reaction with Pl 5? (Total for Question 4 marks) PhysicsndMathsTutor.com
10 This question is about four compounds with molecular formula 4 H 8 O. H 3 OH 2 H 3 H 3 H 2 H 2 HO H 3 H HH 2 OH H 2 HOH H 2 H 2 (a) The compounds which react when heated with a mixture of potassium dichromate(vi) and sulfuric acid are compounds, and. compounds, and. compounds, and. compounds, and. (b) The compound which produces a yellow precipitate when heated with a mixture of iodine and sodium hydroxide is compound. compound. compound. compound. (c) There would not be a significant peak at mass/charge ratio of 15 in the mass spectrum of compound. compound. compound. compound. (Total for Question 3 marks) PhysicsndMathsTutor.com
11 The following tests can be carried out on organic compounds. Warm with 2,4-dinitrophenylhydrazine. Warm with Fehling s or enedict s solution. dd solid sodium carbonate. dd phosphorus(v) chloride, Pl 5. (a) Which test would give a positive result with propanoic acid but not with propan-1-ol? (b) Which test would give a positive result with propanoic acid and with propan-1-ol? (c) Which test would give a positive result with propanal but not with propanone? (Total for Question 3 marks) PhysicsndMathsTutor.com
12 The formulae of some organic compounds labelled to are shown below. H 3 OH H(H 3 ) 2 H 3 O NH 2 (a) Which compound reacts with sodium to form hydrogen? (b) Which compound forms a green complex ion with uso 4 (aq)? (c) Which compound forms an orange precipitate with 2,4-dinitrophenylhydrazine? (Total for Question 3 marks) PhysicsndMathsTutor.com
Pentan-3-one, 2 H 5 O 2 H 5 (Total for Question = 1 mark) H 3 OI 3 (Total for Question = 1 mark) 13 Which of the following reacts with hydrogen cyanide, HN, to make a racemic mixture? Methanal, HHO Ethanal, H 3 HO Propanone, H 3 OH 3 14 Which of the following is a redox reaction? Ethanal reacting with Tollens reagent. Ethanoyl chloride reacting with ammonia. Ethanoic acid reacting with ethanol. Ethanoic acid reacting with sodium hydroxide. (Total for Question = 1 mark) 15 When propanone reacts with iodine in the presence of sodium hydroxide, the crystalline solid product has the formula H 3 I HI 3 H 3 OH 2 I PhysicsndMathsTutor.com
16 Questions (a) to (d) concern the following organic compounds. H 3 H ompound H 3 OH H 3 H 2 H 3 H H 3 ompound H 3 O H H 3 H ompound H 3 O H H 3 O ompound H 3 O H 3 H PhysicsndMathsTutor.com
Select from to the compound that (a) forms iodoform with iodine in the presence of alkali. (b) is chiral. (c) reacts with Tollens reagent. (d) can be oxidized to form a ketone. (Total for Question = 4 marks) PhysicsndMathsTutor.com
17 compound, Q, gives an orange precipitate with 2,4-dinitrophenylhydrazine. ompound Q is resistant to oxidation. On reduction, Q gives a product made up of a pair of optical isomers. Which of the following compounds could be compound Q? H 3 H 2 H 2 OH 3 H 3 H HH(OH)H 3 H 3 H 2 H 2 H 2 HO H 3 H 2 OH 2 H 3 (Total for Question = 1 mark) 18 The compound shown below is found in cocoa beans and in chocolate. Which of the groups listed is not present in its structure? H N O N H 3 O N N H 3 lkyl mide mine Ketone (Total for Question = 1 mark) 19 The compounds below were heated with aqueous sodium hydroxide solution. Which one of them did not give sodium ethanoate, H 3 OONa, as one of the products? H 3 OOH 3 H 3 OH 3 H 3 OOH H Ol (Total for Question = 1 mark) PhysicsndMathsTutor.com
20 Hydrogen cyanide, HN, reacts with propanal, H 3 H 2 HO, in the presence of potassium cyanide, KN. (a) The mechanism for this reaction is nucleophilic addition. nucleophilic substitution. electrophilic addition. electrophilic substitution. (b) The first stage of the mechanism of this reaction is the lone pair of electrons on carbon in N attacking + of propanal. the lone pair of electrons on nitrogen in N attacking + of propanal. the lone pair of electrons on oxygen in propanal attacking + of HN. the lone pair of electrons on oxygen in propanal attacking H + in HN. (c) The product of the reaction is 1-hydroxypropanenitrile. 2-hydroxypropanenitrile. 1-hydroxybutanenitrile. 2-hydroxybutanenitrile. (Total for Question 3 marks) 21 Which of the following does not have hydrogen bonding in a pure sample, but forms hydrogen bonds with water when it dissolves? Propane Propanal Propanol Propanoic acid (Total for Question 1 mark) PhysicsndMathsTutor.com