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OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 1 Which volume of oxygen gas, at room temperature and pressure, is required for complete combustion of 1.25 × 10–3 mol of propan-1-ol? A 105 cm3 B 120 cm3 C 135 cm3 D 150 cm3 Your answer 2 [1] Three of the following displayed formulae represent the same isomer of C3H4Cl2 but one structure represents a different isomer, X. Which displayed formula represents X? Your answer © OCR 2016 [1] Page 1 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 3 Which alcohol will not react with potassium dichromate(VI) in sulfuric acid? A H3CH2CH(OH)CH2CH3 B CH3CH2CH(CH3)CH2OH C (CH3)2CHCH(CH3)OH D (CH3CH2)2C(CH3)OH Your answer 4 [1] A section of a polymer chain is shown below. Identify the monomer that would give rise to this section of addition polymer. A E-But-2-ene B Z-But-2-ene C Methylpropene D Propene Your answer © OCR 2016 [1] Page 2 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 5 Which statement about the two alkenes CH3CH2CH=CH2 and CH3CH=CHCH3 is correct? A Neither exhibits cis–trans isomerism. B Neither may be polymerised. C Neither reacts with bromine to form 1,4-dibromobutane. D Neither reacts with hydrogen to form butane. Your answer 6 [1] Hydrobromic acid reacts with ethene to form bromoethane. What is the best description of the organic intermediate? A It is a free radical. B It contains carbon, hydrogen and bromine. C Its structure is planar. D It is an electrophile. Your answer 7 [1] 1,2-Dibromo-3-chloropropane (DBCP) has been used in the control of earthworms in agricultural land. What would be the best synthesis of DBCP? A CH3CH2CH2Cl + 2Br2 DBCP + 2HBr B CH3CHBrCH2Br + Cl2 DBCP + HCl C CH2=CHCHBr2 + HCl DBCP D CH2=CHCH2Cl + Br2 DBCP Your answer © OCR 2016 [1] Page 3 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 8 The organic compounds labelled A to E below are all produced by living organisms. (a) State the systematic name of compound A. ………………………………………………………………………………… [1] (b) Compound D reacts readily with hydrogen chloride in an addition reaction. Two products are formed in this reaction, but one of the products is formed in much greater amounts than the other. (i) Draw the structure of both possible addition products of this reaction. product 1 © OCR 2016 product 2 [2] Page 4 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry (ii) State and explain which of the two possible products will be formed in greater amounts. Include a diagram of the intermediate in the mechanism of this reaction in your answer. ………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. …………………………..…………………………………………………… 9 [2] A student carries out the following experiment to investigate the reaction between hexane and chlorine. The chlorine is made by reaction of aqueous sodium chlorate(I) with dilute hydrochloric acid. Procedure Observations 1 cm3 of hexane is mixed with 1 cm3 dilute aqueous sodium chlorate(I) in a test-tube. The mixture forms two colourless layers. 1 cm3 dilute hydrochloric acid is slowly added to The acid mixes with the lower layer, the mixture. which turns a pale green colour. The tube is then stoppered and shaken. The pale green colour moves to the upper layer, leaving the lower layer colourless. The tube is placed under a bright light and shaken at regular intervals for about 10 minutes. The stopper is loosened regularly to release any pressure. The pale green colour slowly disappears leaving two colourless layers after about 10 minutes. The reaction of hexane with chlorine took place when the bright light was switched on. © OCR 2016 Page 5 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry (a) Give the skeletal formula of one possible organic product of this reaction. [1] (b) Explain why this type of mechanism is likely to produce a mixture of organic products. ……………………………………………………………………………………………. …………………………………………………………………………………… 10 [1] Alcohols are used in organic synthesis. Pentan-2-ol can be prepared by the alkaline hydrolysis of 2-iodopentane. CH3CH(I)CH2CH2CH3 + NaOH → CH3CH(OH)CH2CH2CH3 + NaI The reaction mixture is boiled for 20 minutes. (a) State the most appropriate technique that could be used to boil the reaction mixture for 20 minutes. ………………………………………………………………………………………. [1] (b) Describe the mechanism for the alkaline hydrolysis of 2-iodopentane. In your answer, include the name of the mechanism, curly arrows and relevant dipoles. name of mechanism: ………………………………………………………… [4] © OCR 2016 Page 6 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 11 (a) Alcohols can be converted into haloalkanes in a substitution reaction. Plan an experiment to prepare approximately 0.1 mol of 2-bromopentane, CH3CHBrCH2CH2CH3, from pentan-2-ol, CH3CH(OH)CH2CH2CH3. Your plan should include a calculation of the mass of alcohol required and details of the chemicals to be used in the reaction. …………………………………………………………………………………………… ……………………………………………………………………………………………. ………………………………………………………………………………….. (b) [2] Alcohols can be converted into alkenes in an elimination reaction. The elimination of H2O from pentan-2-ol forms a mixture of organic products. Give the names and structures of all the organic products in the mixture. Your answer should explain how the reaction leads to the different isomers. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………… © OCR 2016 [6] Page 7 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 12 This question is about cyclic organic compounds. The table shows some information about cycloalkanes (a) These cycloalkanes are members of the same homologous series and have the same general formula (i) What is meant by the term homologous series? ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ………………………………………………………………………………… [2] (ii) State the general formula for these cycloalkanes. .................................................................................................................. [1] (b) The C–C–C bond angles in cyclohexane are 109.5°. State and explain the shape around each carbon atom in cyclohexane. shape................................................................. explanation.............................................................................................................. ………………………………………………………………………………………… [2] © OCR 2016 Page 8 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry (c) In the absence of ultraviolet radiation, cyclopropane undergoes an addition reaction with bromine. Suggest the structure of the organic product formed in this reaction. [1] (d) Cyclohexane can be prepared from hexane. Construct the equation for this reaction …………………………………………………………………………………………. [1] © OCR 2016 Page 9 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 13 Compound G is a branched-chain organic compound that does not have E and Z isomers. Elemental analysis of compound G gave the following percentage composition by mass: C, 55.8%; H, 7.0%; O, 37.2%. The mass spectrum and infrared spectrum of compound G are shown below. Mass Spectrum Infrared Spectrum © OCR 2016 Page 10 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry • Calculate the empirical and molecular formulae for compound G. • Write the formulae for the particles responsible for peak X and peak Y in the mass spectrum. • Draw the structure of compound G. Explain fully how you arrive at a structure for compound G using all the evidence provided. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……….…………………………………………………………………………………………… ……….…………………………………………………………………………………………… ……………….…………………………………………………………………………………… ……….…………………………………………………………………………………………… ……….…………………………………………………………………………………………… ……….…………………………………………………………………………………………… ……….…………………………………………………………………………………………… ……………….…………………………………………………………………………………… ……………………….…………………………………………………………………………… ……………………………….…………………………………………………………………… ……………………………………….…………………………………………………………… ……………………………………………….…………………………………………………… ……………………………………………………….…………………………………………… ……………………………………………………………….…………………………………… ……………………………………………………………………….…………………………… ……………………………………………………………………………….…………………… ……………………………………………………………………………………….…………… © OCR 2016 Page 11 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry ……………………………………………………………………………………………….…… ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ….…………………………………………………………………………………….………. [7] © OCR 2016 Page 12 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry 14 The flowchart shows how 2-methylbut-2-ene can be converted into a number of organic products. (a) Complete the flowchart by drawing an organic structure in the box below. [1] (b) Identify reagent A. ........................................................................................................................... [1] (c) In the flowchart, reaction R forms a mixture of two alcohols that are structural isomers of C5H12O. (i) State the reagents and conditions needed for reaction R. .................................................................................................................. [1] (ii) Suggest why 2-methylbut-2-ene is less soluble in water than either of the structural isomers formed. ....................................................................................................................... ....................................................................................................................... .................................................................................................................. [2] © OCR 2016 Page 13 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry (d) Describe the oxidation reactions of propan-1-ol when using a suitable oxidising agent. Indicate how the use of different reaction conditions can control which organic product forms. Include reagents, observations and equations in your answer. In your equations, use structural formulae and use [O] to represent the oxidising agent. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. ........................................................................................................................... [6] [Total Marks: 52] © OCR 2016 Page 14 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry MARK SCHEME Question 1 Answer C Mks 1 Question Source and Guidance Notes 2 D 1 Q15 - GCE - Chemistry A - Specimen - H032/01 3 D 1 Q16 - GCE - Chemistry A - Specimen - H032/01 4 D 1 Q17 - GCE - Chemistry A - Specimen - H032/01 5 C 1 6 D 1 7 D 1 8(a) 4-methylheptan-3-ol 1 Modified from UCLES, A Level Chemistry, June 1990, Question Paper 9250/1, Question 22 Modified from UCLES, A Level Chemistry, June 1988, Question Paper 9250/3, Question 23 Modified from UCLES, A Level Chemistry, June 1989, Question Paper 9250/3, Question 25 Q22(a) - GCE - Chemistry A - Specimen - H032/01 Q14 - GCE - Chemistry A - Specimen - H032/01 ALLOW 4-methyl-3-heptanol 8(b)(i) 2 Q22(b)(i)- GCE - Chemistry A - Specimen - H032/01 ALLOW any unambiguous structure or formula ALLOW ECF on the second structure for hydrogen atom errors if candidate tries to convert to a displayed/structural formula, but the carbon skeleton must be correct 8(b)(ii) 9(a) correct structure of either possible carbocation intermediate shown the tertiary halogenoalkane (which will be labelled as either product 1 or product 2) is identified as the one formed in greater amounts … because the carbocation more stable on C3 than C2 owtte ✓ any mono or multiple substituted chlorohexane – e.g. © OCR 2016 2 Q22(b)(ii) - GCE - Chemistry A - Specimen - H032/01 Topics Alcohols, haloalkanes and analysis/ Amount of substance Basic concepts and hydrocarbons/ Alkenes Alcohols, haloalkanes and analysis Basic concepts and hydrocarbons/ Alkenes Alkenes Demand H M M M Alkenes Organic synthesis Basic concepts and hydrocarbons Basic concepts and hydrocarbons/ Alkenes/Amount of substance Alkenes M MH If both carbocations are drawn, only one needs to be correct to score the mark ALLOW ECF from (i) for correct justification of product formed in greater amount based on incorrect structures 1 Q23(b)(i) - GCE - Chemistry A - Specimen - H032/01 Basic concepts and hydrocarbons/Alkanes M Page 15 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry Question 9(b) 10(a) 10(b) Answer (because) substitution can replace any H atom /multiple substitution owtte Reflux Nucleophilic substitution Mechanism − Curly arrow from lone pair on OH to δ+ carbon Mks 1 Question Source and Guidance Notes Q23(b)(ii) - GCE - Chemistry A - Specimen - H032/01 IGNORE vague statements about free radical reactions being random ALLOW termination can join alkyl radicals to form larger hydrocarbons owtte 1 4 Q5(a)(i) - GCE - Chemistry A - Specimen - H032/02 Q5(a)(ii) - GCE - Chemistry A - Specimen - H032/02 The curly arrow must start from the oxygen atom of the OH− and must start from either the lone pair or the negative charge atom Topics Basic concepts and hydrocarbons/Alkanes Alcohols, haloalkanes and analysis/Organic synthesis/Planning Alcohols, haloalkanes and analysis/Organic synthesis/Planning Demand M LMH LMH Curly arrow and dipole on C–I bond Correct products DO NOT ALLOW attack by NaOH 11(a) (Minimum) n(pentan-2-ol) required = 0.1× 88 = 8.8g React the alcohol with a mixture of NaBr AND H2SO4 AND warm (to distil off the product) © OCR 2016 2 Q5(b) - GCE - Chemistry A - Specimen - H032/02 ALLOW HBr Alcohols, haloalkanes and analysis/Amount of substance H Page 16 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry Question 11(b) Answer Level 3 (5–6 marks) Applies knowledge of elimination reactions to provide the correct names and structures of all three alkenes AND Full, detailed explanation of formation of both types of isomers linked to the reaction, with clear understanding of both types of isomerism The explanations show a well-developed line of reasoning which is clear and logically structured. The information presented is relevant to the compounds drawn/named. Level 2 (3–4 marks) Applies knowledge of elimination reactions to provide the correct name and structure for pent-1-ene AND Correct structures of stereoisomers of pent-2-ene but full names missing or incorrect AND Explanation of formation of at least one type of isomers in some detail. Mks 6 Question Source and Guidance Notes Q(5)(c) - GCE - Chemistry A - Specimen - H032/02 Indicative scientific points may include: Topics Basic concepts and hydrocarbons/Alkenes Demand LMH • - the elimination can produce a double bond in either • • • the 1- or the 2- position (through combination of the hydroxyl group with a hydrogen from either the 1st or the 3rd carbon) - this leads to the formation of structural isomers (pent1-ene and pent-2-ene) - pent-2-ene exhibits stereoisomerism / E/Z isomerism / cis–trans isomerism because it has two different groups attached to each carbon atom - there are two possible isomers of pent-2-ene and three in total The explanations show a line of reasoning presented with some structure. The information presented is in the most-part relevant to the compounds drawn/named. Level 1 (1–2 marks) Applies knowledge of elimination reactions to name and draw the structures of organic products. Either name OR structure should be correct for two compounds. AND Attempts to explain formation of one type of isomer. The information about isomerism is basic and communicated in an unstructured way. The relationship to the compounds drawn/named may not be clear. 0 marks No response or no response worthy of credit. © OCR 2016 Page 17 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry Question 12(a)(i) 12(a)(ii) 12(b) Answer (series of compounds with the) same functional group OR same/similar chemical properties OR same/similar chemical reactions ✓ each successive/subsequent member differing by CH2 ✓ CnH2n ✓ Tetrahedral ✓ Mks 2 1 2 Demand Basic concepts and hydrocarbons/Alkanes LM Q1(a) - GCE - Chemistry A - June 2014 - F322/01 Q1(b) - GCE - Chemistry A - June 2014 - F322/01 Mark each point independently IGNORE surrounded by four atoms IGNORE four areas of electron charge repel IGNORE four electron pairs repel (one could be lp) DO NOT ALLOW atoms repel 1 Topics Q1(a)(i) - GCE - Chemistry A - June 2014 - F322/01 IGNORE references to physical properties IGNORE has same general formula (in question) DO NOT ALLOW have the same empirical formula OR have the same molecular formula four bonding pairs repel OR four bonds repel✓ 12(c) Question Source and Guidance Notes Q1(c) - GCE - Chemistry A - June 2014 - F322/01 ALLOW correct structural OR displayed OR skeletal formula OR mixture of the above (as long as unambiguous) Basic concepts and hydrocarbons /Alkanes L Basic concepts and hydrocarbons/Alkenes H Basic concepts and hydrocarbons/Alkanes L ALLOW structure of 1,2-isomer IGNORE molecular formula DO NOT ALLOW, structure of 1,1-isomer OR 2,2isomer 12(d) C6H14 C6H12 + H2 1 Q1(d)(i) - GCE - Chemistry A - June 2014 - F322/01 ALLOW correct structural OR displayed OR skeletal formula OR mixture of the above (as long as unambiguous) ALLOW any correct multiple IGNORE state symbols © OCR 2016 Page 18 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry Question 13 Answer Mks 7 Question Source and Guidance Notes Q8(b) - GCE - Chemistry A - June 2014 - F322/01 ANNOTATE ANSWER WITH TICKS AND CROSSES Topics Alcohols, haloalkanes / Analytical techniques Demand MH ALLOW mass of C = 0.558 x 86 or 48 AND mass of H = 0.07 x 86 or 6 AND mass of O = 0.372 x 86 = 32 + charge required for each response ALLOW one mark if both formulae are correct but with no charge/incorrect charge ALLOW any possible fragments that contain C, H and/or O that have the correct mass. E.g. Peak X indicates C2OH+, Peak Y indicates C2H5O+ Unfeasible fragments are not allowed e.g. C3H9 + (too many H atoms) LOOK ON THE SPECTRUM for labelled absorbance which can be given credit Candidates must link absorbance to bond in order to gain the mark ALLOW 1700 cm-1 For 2500–3300 cm-1, ALLOW 2900 cm-1or any stated wavenumber with range 2500–3300cm-1 ALLOW wavenumber range up to 2400–3500cm-1 ALLOW structural, skeletal or displayed formula. DO NOT ALLOW ECF from incorrect molecular formula 14(a) 1 Q7(a) - GCE - Chemistry A - June 2014 - F322/01 ALLOW correct structural OR displayed OR skeletal formula OR mixture of the above DO NOT ALLOW molecular formula ALLOW dichloro or diiodo compound instead © OCR 2016 Alcohols, Halogenoalkanes and Analysis M Page 19 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry Question 14(b) 14(c)(i) 14(c)(ii) Answer Reagent A: correct halogen e.g. Br2 / bromine Steam AND acid catalyst ✓ Mks 1 14(d) Q7(b) - GCE - Chemistry A - June 2014 - F322/01 ALLOW Cl2 if dichloro compound drawn ALLOW I2 if diiodo compound drawn IGNORE state symbols Answer must match box from (a) to score 1 Does not contain OH group(s) OR does not contain hydroxyl group(s) OR is not an alcohol Does not form hydrogen bonds with water Question Source and Guidance Notes 2 Q7(c)(i) - GCE - Chemistry A - June 2014 - F322/01 + ALLOW H / named acid / H2SO4 / H3PO4 ALLOW H2O(g) ALLOW water only if a temperature of 100 °C or above is quoted. IGNORE any temperature given with steam IGNORE pressure Q7(c) - GCE - Chemistry A - June 2014 - F322/01 ALLOW ORA throughout DO NOT ALLOW OH– (ions) / hydroxide (ions) Topics Basic Concepts and Hydrocarbons Demand L,M Basic Concepts and Hydrocarbons L,M,H Basic Concepts and Hydrocarbons ‘Does not form hydrogen bonds’ is not sufficient’ 6 Q7(d) - GCE - Chemistry A - June 2014 - F322/01 ANNOTATE ANSWER WITH TICKS AND CROSSES ETC ALLOW H2SO4 and K2Cr2O7 Alcohols, Halogenoalkanes and Analysis L,M,H ALLOW correct displayed formula OR correct structural formula OR skeletal formula OR a mixture of the above DO NOT ALLOW molecular formulae ALLOW C3H7OH for propan-1-ol in equations DO NOT ALLOW CH3CH2COH for aldehyde IGNORE further oxidation of aldehyde ALLOW CH3CH2CO2H for carboxylic acid TOTAL © OCR 2016 52 Page 20 OCR AS/A Level Chemistry A (H032/H432) Module 4 Topic Test – Core Organic Chemistry OCR Resources: the small print OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board, and the decision to use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or omissions within these resources. We update our resources on a regular basis, so please check the OCR website to ensure you have the most up to date version. © OCR 2016 © OCR 2016 Page 21