TJC 2025 Structured Remedial Organic Alcohol and Carboxylic acid Student

1 CHEMISTRY STRUCTURED REMEDIAL TOPIC: ORGANIC CHEMISTRY (ALCOHOL AND CARBOXYLIC ACID) Multiple Choice Questions (Time allocation: 12 min) 1 Which pairs of molecules are constitutional isomers? 1 CH3CH2CH(CH3)2 and (CH3)4C 2 propanoic acid and methyl ethanoate 3 and A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 2 How many alcohol isomers are there with the molecular formula C3H8O2? A 4 B 5 C 6 D 7 3 What is the minimum number of moles of oxygen molecules required for the complete combustion of one mole of propanol? A 3.0 B 4.5 C 5.0 D 8.0 20 Name: _______________________ Class: __________

2 4 Compound Y • has the empirical formula CH2 • has an Mr of 56.0 • forms two alcohols that have different structural formulae when reacted with steam What is compound Y? A B C D 5 The diagram shows the products of two reactions of ethanol, C2H5OH. C2H4 C2H5OH C2H4O2 Which types of reaction are reaction X and Y? X Y A elimination oxidation B elimination reduction C reduction elimination D oxidation elimination X Y

3 6 Pentaerythritol is used as an intermediate in the manufacture of paint. It has the molecular formula C5H12O4 and contains four primary alcohol groups. After prolonged heating under reflux with an excess of Cr 2O72−/H+, it forms compound X which also has five carbon atoms. What is the molecular formula of compound X? A C5H4O8 B C5H4O4 C C5H8O4 D C5H8O8 7 An ester of molecular formula C 4H8O2 was produced by the reaction of an alcohol with a carboxylic acid. alcohol acid 1 methanol propanoic acid 2 ethanol ethanoic acid 3 propanol methanoic acid Which of the following could be the alcohol and the acid? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only

4 8 An ester has the structure shown. Which two compounds will react together to form this ester? 1 butanoic acid 2 3-methylbutanoic acid 3 butan-2-ol 4 2-methylbutanol A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 Time allocation: 4.5 min 9 Put a tick (√) in each of the correct boxes to show in which of the following would a reaction occur. ethene ethanol ethanoic acid Br2(aq), rtp in the dark KMnO4(aq), dilute H2SO4, heat K2Cr2O7(aq), dilute H2SO4, heat Na(s), rtp NaOH(aq), rtp Na2CO3(s), rtp [Total: 3]

5 Time allocation: 9 min 10 A student is given two unlabelled bottles containing colourless liquids. One of the liquids is butan-1-ol and the other one is butanoic acid. The student identified two different simple chemical tests that would distinguish between each of the two substances. (a) Describe the reagents and conditions for a chemical test that gives a positive result only with butan -1-ol. Describe what would be observed and write a balanced chemical equation for the reaction occurring. [3]