Multiple Choice Questions (MCQ) topic quiz Polymers and life Instructions and answers for teachers These instructions cover the student activity section which can be found on page 9. This Lesson Element supports OCR A Level Chemistry B (Salters). When distributing the activity section to the students either as a printed copy or as a Word file you will need to remove the teacher instructions section. The Activity This Lesson Element is a teaching and learning resource containing 10 multiple choice questions (MCQs) on the theme of polymers and life. Some questions might require synoptic thinking, using knowledge and ideas from various topics across the full A Level content. This resource can be used to test and consolidate understanding at the end of a topic or to revisit and refresh knowledge at a later point in the course. Learning Outcomes This Lesson Element relates to the specification learning outcomes PL(c), PL(f), PL(i), PL(k), PL(l), PL(m), PL(n), PL(q), PL(s). Introduction Multiple choice questions allow rapid coverage of a wide range of sub-topics. Contrary to a widespread belief among students, multiple choice questions are not necessarily easy – they can be easy, moderate or difficult. The questions are written so that the incorrect answers are plausible distractors based on common errors or misconceptions. The questions in this quiz cover topics mainly from specification sections: Polymers and life. Version 1 1 © OCR 2016 Multiple Choice Questions (MCQ) topic quiz - answers 1. What is the name of the polymer formed from dihexanoyl chloride and 1,4-diaminobutane? A nylon-6 The learner has not appreciated that this is a co-polymer. B nylon-4,6 Correct answer: The amine has four carbons and the acyl chloride has six. C nylon-6,4 The learner has confused the order of the numbers. D nylon-6,6 The learner has possibly counted the nitrogen atoms as part of the numbering system in 1,4-diaminohexane. Your answer 2. Which molecule is a primary amide? A CH3CH(NH2)CH3 The learner is confused between a primary amide and a primary amine. B CH3NHCOCH3 This is a secondary amide; the learner may be confused about the definition of a primary amide. C C6H5CONH2 Correct answer: This is a derivative of a carboxylic acid with the –OH group replaced with a NH2 group. D CH3NHCH2CH3 This is a secondary amine. The learner may have simply guessed at something that looks a little unfamiliar. Your answer Version 1 B 2 C © OCR 2016 3. Which statement is true about the structure of a DNA double helix? A Adenine pairs with uracil. Uracil is present in RNA only. B Bases are joined in the middle by condensation reactions. Bases are joined by hydrogen bonding; condensation reactions link the nucleotides together. C The backbone is made up of phosphate and ribose. Ribose is present in RNA only. D The molecule is negatively charged overall. Correct answer: The phosphate groups make the backbone negatively charged, which aids solubility. Your answer 4. D A student carries out the hydrolysis of an ester, benzyl ethanoate, under acidic conditions. Some tests were carried out on the reaction mixture and it was decided that the reaction had not gone to completion. Which of the results below provides proof that this is the case? A A broad peak above 3000 cm–1 on the infrared spectrum. This indicates the presence of an alcohol but does not indicate whether or not any unhydrolysed ester remains in the mixture. B Two spots on a thin layer chromatography plate. This would confirm that the reaction had gone to completion as the ester would no longer be present but the alcohol and carboxylic acids would be. C Three spots on a thin layer chromatography plate. Correct answer: This confirms that unreacted ester is still present alongside the alcohol and carboxylic acid. D A peak on the mass spectrum with an m/z ratio of 60. This confirms the presence of ethanoic acid but this fragment could be present at any stage. Your answer Version 1 3 C © OCR 2016 5. Which molecule is optically active? A B C D A Two carbons have three other carbons attached; however the molecule is symmetrical so they are not chiral B Correct answer: The carbon with the –OH group attached has three other groups attached, making it a chiral centre. C This molecule is completely planar and cannot have chiral carbons. D The learner is perhaps thinking that a carbon on the benzene ring is chiral, but there are only three groups attached due to the presence of double bonding. Your answer Version 1 4 B © OCR 2016 6. A compound has the molecular formula C5H10O and the 1H-NMR spectrum contains four peaks. The compound could be: A 3-methylbutan-2-one 3-Methylbutan-2-one would have one environment for the methyl adjacent to the carbonyl, another for the hydrogen on the third carbon but the two methyl groups attached to the end of the chain would be identical environments due to rotational symmetry. B pentanal Pentanal would have five different hydrogen environments. The learner has most likely forgotten the hydrogen attached to the aldehyde group. C pentan-2-one Correct answer: One carbon would have a carbonyl attached; the other four carbons would each present a different hydrogen environment since the molecule is not symmetrical. D pentan-3-one The molecule is symmetrical about the central carbonyl group and so only two hydrogen environments exist. Your answer Version 1 5 C © OCR 2016 7. The graph opposite shows the effect of substrate concentration for an enzyme-catalysed reaction. Which statement best explains the shape of the graph? A The enzymes are denatured at higher substrate concentrations. The learner is confused about the meaning of the term ‘denatured’. B The enzyme active sites become saturated with substrate at higher concentrations. Correct answer: At high concentrations the reaction is zero order with respect to substrate concentration as the maximum number of active sites are occupied. C The substrate concentration does not affect rate. The concentration does affect rate at lower concentrations; the learner is thinking in terms of the plateau of the graph only. D There is a competitive inhibitor present in the mixture. The graph would be the same shape in the presence of an inhibitor; however the presence of the inhibitor does not determine the shape of the graph itself, only the time taken for the graph to plateau. Your answer 8. Which hydrolysis reaction could result in both the organic species being produced as uncharged molecules? A Hydrolysis of an amide under acidic conditions. The learner has not appreciated that the amine molecule would be protonated under acidic conditions. B Hydrolysis of an amide under alkaline conditions. The learner has not appreciated that the carboxylic acid molecule would be deprotonated under alkaline conditions. C Hydrolysis of an ester under acidic conditions. Correct answer: Neither the carboxylic acid nor the alcohol would react with the acid. D Hydrolysis of an ester under alkaline conditions. The learner has not appreciated that the carboxylic acid would be deprotonated under alkaline conditions. Your answer Version 1 B 6 C © OCR 2016 9. Which two reagents could be used to prepare the ester propyl ethanoate? A ethanoic acid and propan-2-ol This would produce an isomer of propyl ethanoate but would not contain a straight chain propyl group. B ethanoic anhydride and propan-1-ol Correct answer: This would produce propyl ethanoate with ethanoate ions as a side product. C ethanoyl chloride and 1-aminopropane This would produce the amide propyl ethanamide. D propanoic acid and ethanol The learner is confused about the naming system for esters as this would produce ethyl propanoate. Your answer 10. B Which statement(s) is/are true for all naturally occurring amino acids? Statement 1: They can behave as acids and bases Statement 2: They rotate the plane of polarised light Statement 3: They have no net charge when dissolved in water A 1, 2 and 3 Statement 1 is true. Statement 2 is untrue because glycine does not have a chiral centre. Statement 3 is untrue – although the –NH3+ and –COO– groups of the zwitterion do cancel out, some amino acids contain acidic or basic groups in their side chain which are ionised. B only 1 and 2 Statement 2 is untrue (see above) – many learners forget that the side chain can be a hydrogen atom. C only 2 and 3 Statement 2 is untrue (see above). Statement 3 is untrue but many learners think of the ‘R’ group of amino acids as not containing acidic or basic groups. D only 1 Correct answer: Statement 1 is the only true statement (see above). Your answer Version 1 7 D © OCR 2016 This resource has been produced as part of our free Chemistry teaching and learning support package. All the Chemistry teaching and learning resources, including delivery guides, topic exploration packs, lesson elements and more are available on the qualification webpages. If you are looking for examination practice materials, you can find Sample Assessment Materials (SAMs) and a link to the Practice Papers on the qualification webpages: Chemistry A, Chemistry B. We’d like to know your view on the resources we produce. By clicking on ‘Like’ or ‘Dislike’ you can help us to ensure that our resources work for you. When the email template pops up please add additional comments if you wish and then just click ‘Send’. Thank you. 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OCR acknowledges the use of the following content: n/a Please get in touch if you want to discuss the accessibility of resources we offer to support delivery of our qualifications: resources.feedback@ocr.org.uk Version 1 8 © OCR 2016 Multiple Choice Questions (MCQ) topic quiz Polymers and life Learner Activity 1. What is the name of the polymer formed from dihexanoyl chloride and 1,4-diaminobutane? A nylon-6 B nylon-4,6 C nylon-6,4 D nylon-6,6 Your answer 2. Which molecule is a primary amide? A CH3CH(NH2)CH3 B CH3NHCOCH3 C C6H5CONH2 D CH3NHCH2CH3 Your answer Version 1 9 © OCR 2016 3. Which statement is true about the structure of a DNA double helix? A Adenine pairs with uracil. B Bases are joined in the middle by condensation reactions. C The backbone is made up of phosphate and ribose. D The molecule is negatively charged overall. Your answer 4. A student carries out the hydrolysis of an ester, benzyl ethanoate, under acidic conditions. Some tests were carried out on the reaction mixture and it was decided that the reaction had not gone to completion. Which of the results below provides proof that this is the case? A A broad peak above 3000 cm–1 on the infrared spectrum. B Two spots on a thin layer chromatography plate. C Three spots on a thin layer chromatography plate. D A peak on the mass spectrum with an m/z ratio of 60. Your answer Version 1 10 © OCR 2016 5. Which molecule is optically active? A B C D Your answer 6. A compound has the molecular formula C5H10O and the 1H-NMR spectrum contains four peaks. The compound could be: A 3-methylbutan-2-one B pentanal C pentan-2-one D pentan-3-one Your answer Version 1 11 © OCR 2016 7. The graph below shows the effect of substrate concentration for an enzymecatalysed reaction. Which statement best explains the shape of the graph? A The enzymes are denatured at higher substrate concentrations. B The enzyme active sites become saturated with substrate at higher concentrations. C The substrate concentration does not affect rate. D There is a competitive inhibitor present in the mixture. Your answer 8. Which hydrolysis reaction could result in both the organic species being produced as uncharged molecules? A Hydrolysis of an amide under acidic conditions. B Hydrolysis of an amide under alkaline conditions. C Hydrolysis of an ester under acidic conditions. D Hydrolysis of an ester under alkaline conditions. Your answer Version 1 12 © OCR 2016 9. Which two reagents could be used to prepare the ester propyl ethanoate? A ethanoic acid and propan-2-ol B ethanoic anhydride and propan-1-ol C ethanoyl chloride and 1-aminopropane D propanoic acid and ethanol Your answer 10. Which statement(s) is/are true for all naturally occurring amino acids? Statement 1: They can behave as acids and bases Statement 2: They rotate the plane of polarised light Statement 3: They have no net charge when dissolved in water A 1, 2 and 3 B only 1 and 2 C only 2 and 3 D only 1 Your answer Version 1 13 © OCR 2016