Zadanie 2a
(a) Outline two features of this experiment that ensure that the propanal intermediate is not a major product.
- Materiał graficzny
Oxidation of alcohols
Write equations for the oxidation of primary alcohols to aldehydes and then carboxylic acids and of secondary alcohols to ketones with acidified dichromate(VI), explain why tertiary alcohols resist oxidation, and relate distillation versus reflux to the product obtained.
Tę umiejętność sprawdzają 24 zadania wzorowane na arkuszach IB z lat 2022–2026.
Zadania sprawdzające tę umiejętność: 24 Otwórz w wyszukiwarce z filtrami
Zadanie 3d
Pentan-2-ol will react with acidified potassium dichromate, K2Cr2O7, which is an oxidizing agent. (i) State the name of the product of this reaction. (ii) Explain how infrared spectroscopy could be used to distinguish between pentan-2-ol and the product…
Zadanie 34
When heated under reflux with excess acidified potassium dichromate(VI), how many of the structural isomers of the alcohol C5H11OH are oxidized to a carboxylic acid? A. 3 B. 7 C. 4 D. 8
Zadanie 8b
The compound X shown below occurs naturally in cocoa and coffee and is used as a flavouring agent. (i) State the name of the functional group found in compound X. (ii) Deduce the IUPAC name of X. (iii) Deduce how many signals the NMR spectrum of X…
- Materiał graficzny
Zadanie 36
Which alcohol and which conditions would give the highest yield of 3-methylbutanoic acid on oxidation with acidified potassium dichromate(VI)? A. 3-methylbutan-2-ol, reflux B. 3-methylbutan-1-ol, distillation C. 3-methylbutan-1-ol, reflux D.…
Zadanie 38
Which change represents oxidation of the functional group? A. CH3COCH3 → CH3CH(OH)CH3 B. CH3CH(OH)CH3 → CH3COCH3 C. CH3CH2COOH → CH3CH2CHO D. CH3CH=CH2 → CH3CH2CH3
Zadanie 3e
A compound used to make polymers, hexanedioic acid, can be produced by a series of reactions starting from cyclohexane. (i) Deduce how reactant A is related to hex-1-ene. (ii) For the C=O functional group present in intermediate C, state its structural…
- Tabela do uzupełnienia
- Materiał graficzny
Zadanie 35
Which compounds are oxidized when heated with acidified potassium dichromate(VI) solution? I. CH3CH2C(CH3)2OH II. (CH3)2CHCH2OH III. CH3CH(OH)CH3 A. I and II only B. I and III only C. II and III only D. I, II and III
Zadanie 1e
When A is refluxed with excess acidified potassium dichromate(VI), K2Cr2O7, the product is compound E, whose molar mass is greater than that of A. From this information alone, identify one functional group in E.
Zadanie 2e
Pentan-2-ol is optically active. (i) Sketch the two enantiomers of pentan-2-ol, showing how they are related. (ii) Deduce the organic product formed in each case when pentan-1-ol and pentan-2-ol are refluxed with acidified potassium dichromate(VI).…
Zadanie 34
Which compound can be oxidized to a carboxylic acid by heating under reflux with an excess of an acidified oxidizing agent? A. CH3CH(OH)CH2CH3 B. (CH3)3COH C. (CH3)2CHCH2OH D. CH3COCH2CH3
Zadanie 3b
Identify the reagents for each step.
Zadanie 21c
A detector tube for propan-2-ol vapour in workplace air contains orange dichromate ions, which turn green as they are reduced to chromium(III) ions. Cr2O72−(aq) + 14 H+(aq) + 6 e− → 2 Cr3+(aq) + 7 H2O(l) Deduce the half-equation for the oxidation of…
Zadanie 27b
Propan-1-ol is heated under reflux with an excess of acidified oxidizing agent. Identify the two organic compounds formed, one after the other, in the course of the oxidation.
Zadanie 35
What is the correct order of reaction types in the following sequence? A. I: addition; II: substitution; III: oxidation B. I: substitution; II: addition; III: oxidation C. I: addition; II:…
Zadanie 6a
Butanone can be synthesized from but-1-ene in a two-stage process. In the first stage but-1-ene reacts with water and sulfuric acid to form an intermediate compound X. In the second stage X reacts with reagent B to form butanone. (i) Draw the structural…
- Materiał graficzny
Zadanie 6a
Butanone can be synthesised from but-1-ene in a two-stage process. In the first stage the alkene reacts with water in the presence of sulfuric acid to form the intermediate compound [X]; in the second stage [X] is converted into butanone by reagent B. (i) Draw…
- Materiał graficzny
Zadanie 16e
Menthol is a secondary alcohol used in cough lozenges. A chemist heated menthol with an oxidizing agent and isolated the product, which is either unreacted menthol or its oxidation product menthone. The structures of the two compounds and the IR spectrum of…
- Materiał graficzny
Zadanie 33
2-Methylpropan-1-ol is heated with an acidified oxidizing agent and the first product is distilled off as it forms. What is this product? A. (CH3)2CHCOOH B. (CH3)2CHCHO C. (CH3)2CHCH2OH D. CH3COCH2CH3
Zadanie 33
Butan-1-ol is heated with an acidified oxidizing agent, and the first product formed is distilled off as soon as it forms. Which compound is collected? A. CH3CH2COCH3 B. CH3CH2CH2CH2OH C. CH3CH2CH2CHO D. CH3CH2CH2COOH
Zadanie 5c
Deduce what would be observed when each of Compound B and pentan-2-ol is warmed separately with acidified aqueous potassium dichromate(VI).
- Materiał graficzny
Zadanie 32
Which sequence of reagents converts but-1-ene into butanone? Each reagent is added to the product of the previous reaction. A. HBr, then NaOH(aq), then acidified K2Cr2O7(aq) B. HBr, then acidified K2Cr2O7(aq), then…
Zadanie 34
Which procedure is best for converting butan-1-ol into butanoic acid? A. Heat under reflux with an acidified oxidizing agent B. Heat under reflux with a reducing agent C. Heat with an acidified oxidizing agent and distil off the product as it forms D. Heat…
Zadanie 34
Which conditions best favour the oxidation of butan-1-ol to butanal rather than to butanoic acid? A. Excess oxidizing agent, heated under reflux B. Excess oxidizing agent, heated with the product distilled off as it forms C. Limited oxidizing agent, heated…