13.2. Characteristic organic reactions
A subsection of Chemistry, 9701, through 13. An introduction to AS Level organic chemistry
Listing 10 of 29 questions
Organohalogen compounds can undergo hydrolysis. R–Cl + H2O → R–OH + HCl State the relative rates of hydrolysis of the following compounds. CH3CH2CH2Cl CH3CH2COCl C6H5Cl Explain your answer. Aminolaevulinic acid is involved in the synthesis of haemoglobin and chlorophyll. OH O O H2N aminolaevulinic acid Name the three functional groups in aminolaevulinic acid. Aminolaevulinic acid reacts readily with bromoethane. Show the mechanism of the fi rst step of this reaction on the diagram. Include all necessary curly arrows, lone pairs and relevant dipoles. OH O O H2N OH O O HN H3C H3C CH2 Br intermediate Name the mechanism in . Identify the non-organic product formed in this reaction. Three reactions of aminolaevulinic acid are shown. Draw the structures of the products W, X and Y in the boxes below. OH O O H2N CH3COCl NaBH4 HCl , warm W X Y aminolaevulinic acid Aminolaevulinic acid can undergo polymerisation. Draw the structure of the polymer showing two repeat units. The linkages between the monomer units should be shown fully displayed.
9701_w14_qp_41
THEORY
2014
Paper 4, Variant 1
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Organohalogen compounds can undergo hydrolysis. R–Cl + H2O → R–OH + HCl State the relative rates of hydrolysis of the following compounds. CH3CH2CH2Cl CH3CH2COCl C6H5Cl Explain your answer. Aminolaevulinic acid is involved in the synthesis of haemoglobin and chlorophyll. OH O O H2N aminolaevulinic acid Name the three functional groups in aminolaevulinic acid. Aminolaevulinic acid reacts readily with bromoethane. Show the mechanism of the fi rst step of this reaction on the diagram. Include all necessary curly arrows, lone pairs and relevant dipoles. OH O O H2N OH O O HN H3C H3C CH2 Br intermediate Name the mechanism in . Identify the non-organic product formed in this reaction. Three reactions of aminolaevulinic acid are shown. Draw the structures of the products W, X and Y in the boxes below. OH O O H2N CH3COCl NaBH4 HCl , warm W X Y aminolaevulinic acid Aminolaevulinic acid can undergo polymerisation. Draw the structure of the polymer showing two repeat units. The linkages between the monomer units should be shown fully displayed.
9701_w14_qp_42
THEORY
2014
Paper 4, Variant 2
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CompoundT is an isomer of C6H12. T Name T. Draw the skeletal formula of a structural isomer of T that shows cis-trans isomerism.  Each carbon atom in T forms a sigma (σ) bond to at least one other carbon atom, as shown. C C H3C H3C CH3 CH3 On the diagram, draw the orbitals that represent the pi (π) bond that is also present in T.  State the hybridisation of the two carbon atoms between which the pi (π) bond forms. A reaction scheme starting with T is shown. Reaction2 occurs in the presence of a catalyst; knowledge of the mechanism for this reaction is not required. T U reaction 1 reaction 2 catalyst HO OH V O Give the reagentand conditions for reaction1. State and explain how 2,4-dinitrophenylhydrazine (2,4-DNPH) can be used to detect the presence of V as a product of reaction 2. The progress of reaction2 can be monitored by infrared spectroscopy. The absorption caused by O–H bonds is always present because water is used as a solvent. Identify two absorptions, and the bonds responsible for these absorptions, whose appearance will change significantly during the reaction.  V is used in a wide range of organic reactions. Some reactions of V are shown. reaction 3 reaction 4 NaBH4 alkaline aqueous I2 reaction 5 reaction 6 dehydration addition polymerisation V X O OH Y Z W O O– V and W are colourless and soluble in water. State what you would observe in reaction3. Reaction3 is a redox reaction. Identify which of the reactants is reduced in this reaction. Construct an equation for reaction4. Use in the equation to represent an atom of hydrogen from NaBH4. C6H12O + ��������������������������������������������������������������������������������������������������������������������� X is a mixture of two optical isomers. Draw the two optical isomers in the boxes provided.  Both optical isomers of X can be dehydrated to form a single product, Y. Give the reagentand conditions required for reaction 5. Y can form an addition polymer Z. Draw one repeat unit of Z.  Reaction6 does not proceed quickly at room temperature. Suggest why this is the case. 
9701_w21_qp_22
THEORY
2021
Paper 2, Variant 2
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State the reactants and conditions for two different types of reactions that both produce diethylamine, CH3CH2NHCH2CH3. reaction one reaction two Describe the relative basicities of diethylamine, phenylamine and ammonia in aqueous solution. Explain your answer in terms of structure. least basic most basic explanation Phenylamine reacts with HNO2at 4° C to form compound P. Compound P reacts with phenol under alkaline conditions at 4° C. The product of this reaction is acidified, forming azo compound Q. Draw the structure of compound Q. Circle the azo group on your structure. State one use of an azo compound such as Q. compound Q: An azo compound can be used . CH3CH2NHCH2CH3 reacts with ethanoyl chloride, CH3COCl, to give the amide N,N-diethylethanamide, CH3CON(C2H5)2. An incomplete description of the mechanism of this reaction is shown in . box one reactants N H C2H5 C2H5 Cl C O H3C N H C2H5 C2H5 Cl C O H3C box two intermediate box three products and O C N H3C C2H5 C2H5 Complete the mechanism in . You should include: ● all relevant dipoles (δ+ and δ–) and full electric charges (+ and –) on the species in box one and in box two ● all relevant lone pairs on the species in box one and in box two ● all relevant curly arrows to show the movement of electron pairs in box one and in box two ● the formula of the second product in box three. Name this mechanism.
9701_w23_qp_42
THEORY
2023
Paper 4, Variant 2
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Questions Discovered
29