In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choices:
(a) Assertion and Reason both are correct and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are wrong.
(c) Assertion is correct but Reason is wrong.
(d) Assertion is wrong but Reason is correct.
(e) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion. .
Assertion (A): Addition reaction of water to but-l-ene in acidic medium yields-butan-l-ol.
Reason (R): Addition of water in acidic medium proceeds through the formation of primary carbocation.
(b) Addition of water to but-l-ene in acidic medium yields butan-2-ol.
Addition of water proceeds through formation of secondary carbocation.
Assertion (A): Ethanol is a weaker acid than phenol.
Reason (R): Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH.
Assertion (A): Boiling points of alcohols and ethers are high.
Reason (R): They can form intermolecular hydrogen bonding.
Name the enzymes and write the reactions involved in the preparation of ethanol from sucrose by fermentation.
Explain why is OH group in phenols more strongly held as compared to OH group in alcohols.
Assertion (A): Bond angle in ethers is slightly less than the tetrahedral angle. Reason (R): There is a repulsion between the two bulky (-R) groups.
Explain why alcohols and ethers of comparable molecular mass have different boiling points.
Explain a process in which a biocatalyst is used in industrial preparation of a compound known to you.
Assertion (A): IUPAC name of the compound
Reason (R): In IUPAC nomenclature, ether is regarded as hydrocarbon derivative in which a hydrogen atom is replaced by -OR or -OAr group [where R = alkyl group and Ar = aryl group]
Preparation of alcohols from alkenes involves the electrophilic attack on alkene carbon atom. Explain its mechanism.
Write structures of the compounds whose IUPAC names are as follows:
(i)2-Methylbutan-2-ol
(ii)l-Phcnylpropan-2-ol
(iii)3,5-DimethyIhexane-l,3,5-triol
(iv)2,3-Dicthylphenol
(v)1-Ethoxypropane
(vi)2-Ethoxy-3-methylpentane
(vii) Cyclohexylmethanol
(viii) 3-Cyclohexylpcntan-3-ol
(ix)Cyclopcnt-3-en-l-ol
(x)4-ChIoro-3-ethylbutan-l-ol
Which of the following are used to convert RCHO into RCH2OH?
(a) H2/Pd
(b) LiAlH4
(c) NaBH4
(d) Reaction with RMgX followed by hydrolysis
Alcohols react with active metals, e.g., Na, K, etc., to give corresponding alkoxides. Write down the decreasing order or reactivity of sodium metal towards primary, secondary and tertiary alcohols.
Write the equations involved in the following reactions:
(i) Reimer-Tiemann reaction
(ii) Kolbe's reaction
Name the reagents used in the following reactions:
(i)Oxidation of a primary alcohol to carboxylic acid.
(ii)Oxidation of a primary alcohol to aldehyde.
(iii)Brominationofphenolto2,4,6-tribromophenol
(iv)Benzyl alcohol to benzoic acid.
(v)Dehydration of propan-2-oI to propene.
(vi)Butan-2-one to butan-2-oL .
How is 1-propoxypropane synthesised from propan-l-ol? Write the mechanism of this reaction.
Phenol can be distinguished from ethanol by the reactions with ………….
(a) Br2/water (b) Na
(c) Neutral FeCl3 (d) All of these
Assertion (A): Like bromination of benzene, bromination of phenol is also carried out in the presence of Lewis acid.
Reason (R): Lewis acid polarizes the bromine molecule.
Show how are the following alcohols prepared by the reaction of a suitable Grignard reagent on methanal ?
Alcohols are comparatively more soluble in water than hydrocarbons of comparable molecular masses. Explain this fact.
While separating a mixture of ortho and para nitrophenols by steam distillation, name the isomer which will be steam volatile. Give reason.
Arrange water, ethanol and, phenol in increasing order of acidity and give reason for your answer.
Assertion (A): p-Nitrophcnol is more acidic than phenol.
Reason (R): Nitro group helps in the stabilization of the phenoxide ion by dispersal of negative charge due to resonance.
Assertion (A): Phenols give o-nitrophenol and p-nitrophenol on nitration with cone. HNO3 and H2SO4 mixture.
Reason (R): -OH group in phenol is o-,p-directing.
Predict the major product of acid catalysed dehydration of
(i) 1-nicthylcyclohcxanoland
(ii) butan-1-ol
Write the reactions of Williamson synthesis of 2-ethoxy-3-methylpentane starting from ethanol and 3-methylpentan-2-ol.
Give equations of the following reactions:
(i)Oxidation of propan-l-ol with alkaline KMnO4 solution.
(ii)Bromine in CS2 with phenol.
(iii)Dilute HNO3 acid with phehoL
(iv)Treating phenol with chloroform in presence of aqueous NaOH.
How are the following conversions carried out?
(i) Propene —> Propan -2-ol
(ii) Benzyl chloride —> Benzyl alcohol
(iii) Ethyl magnesium chloride —> Propan-l-ol
(iv) Methyl magnesium bromide —> 2-Methylpropan-2-ol
Mark the correct increasing order of reactivity of the following compounds with HBr/HCl.
Which of the following reagents can be used to oxidize primary alcohols to aldehydes?
(a) CrO3 in anhydrous medium
(b) KMnO4 in acidic medium
(c) Pyridinium chlorochromate
(d) Heat in the presence of Cu at 573 K
