Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 1.
IUPAC name of
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 1
(a) 3-propylbutan-l-ol
(b) 2-ethylpentan-l-ol
(c) 3-methyl hydroxyhexane
(d) 2-ethyl-2-propyl ethanol
Answer:
(a) 3-propylbutan-l-ol

Question 2.
A compound C6H4O2 has two tertiary alcoholic groups. The IUPAC name of this compound is
(a) 2, 3-dimethyl-l, 2-butanediol
(b) 3, 3-dimethyl-l, 2-butanediol
(c) 2, 3-dimethyl-2, 3-butanediol
(d) 2-methyl-2, 3-pentanediol
Answer:
(c) 2, 3-dimethyl-2, 3-butanediol

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 3.
Which of the following is phenol ?
(a) Cresol
(b) Catechol
(c) Benzenol
(d) All of these
Answer:
(d) All of these

Question 4.
The C—O—C angle in ether is about
(a) 180°
(b) 190°28′
(c) 110°
(d) 105°
Answer:
(c) 110°

Question 5.
The best method to prepare 3-methylbutan-2-ol from 3- methylbut-l-ene is
(a) addition of water in presence of dil. H2SO4
(b) addition of HCl followed by reaction with dil. NaOH
(c) hydroboration-oxidation reaction
(d) Reimer-Tiemann reaction
Answer:
(a) addition of water in presence of dil. H2SO4

Question 6.
An alkene CH3CH = CH2 is treated with B2H6 in presence of H202. The final product formed is
(a) CH3CH2CHO
(b) CH3CH(OH)CH3
(c) CH3CH2CH2OH
(d) (CH3CH2CH2)3B
Answer:
(c) CH3CH2CH2OH

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 7.
Which reducing agent is used for the following conversion ?
RCOOH → RCH 2OH
(a) LiAlH4
(b) NaBH4
(c) K2Cr2O7
(d) KMnO4
Answer:
(a) LiAlH4

Question 8.
Tertiary butyl alcohol can be prepared by the reaction of
(a) acetaldehyde and ethyl magnesium iodide
(b) acetone and methyl magnesium iodide
(c) formaldehyde and propyl magnesium iodide
(d) butanone and methyl magnesium iodide
Answer:
(b) acetone and methyl magnesium iodide

Question 9.
1-Phenylethanol can be prepared by the reaction of benzaldehyde with
(a) methyl bromide
(b) ethyl iodide and magnesium
(c) methyl iodide and magnesium
(d) methyl bromide and aluminium bromide
Answer:
(c) methyl iodide and magnesium

Question 10.
Propanone on reaction with alkyl magnesium bromide followed by hydrolysis will produce
(a) primary alcohol
(b) secondary alcohol
(c) tertiary alcohol
(d) carboxylic acid
Answer:
(c) tertiary alcohol

Question 11.
In the following sequence of reactions,
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 2
the compound Q formed will be
(a) aniline
(b) phenol
(c) benzaldehyde
(d) benzene sulphonic acid
Answer:
(b) phenol

Question 12.
Cumene on reaction with oxygen followed by hydrolysis gives
(a) CH3OH and C6H5COCH3
(b) C6H5OH and (CH3)2O
(c) C6H5OCH3 and CH3OH
(d) C6H5OH and CH3COCH3
Answer:
(d) C6H5OH and CH3COCH3

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 13.
The decreasing order of boiling points of the following alcohols is
(a) 3-methylbutan-2-ol > 2-methylbutan-2-ol > pentain- l-ol            .
(b) pentan-l-ol > 3-methylbutan-2-ol > 2-methylbutan- 2-ol
(c) 2-methyIbutan-2-ol > 3-methylbutan-2-ol > pentan- l-ol
(d) 2-methylbutan-2-ol > pentan-l-ol > 3-methylbutan- 2-ol
Answer:
(b) pentan-l-ol > 3-methylbutan-2-ol > 2-methylbutan- 2-ol

Question 14.
Arrange the following compounds in increasing order of boiling points. Propan-l-ol, butan-l-ol, butan-2-ol,
pentan-1-ol.
(a) Propan-1-ol, butan-2-ol, butan-1-ol, pentan-1-ol
(b) Propan-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol
(c) Pentan-1-ol, butan-2-ol, butan-1-ol, propan-1-ol
(d) Pentan-1-ol, butan-1,-ol, butan-2,-ol, propan-1-ol
Answer:
(a) Propan-1-ol, butan-2-ol, butan-1-ol, pentan-1-ol

Question 15.
ortho-Nitrophenol is less soluble in water than p-and m-nitrophenols because
(a) o-nitrophenol shows intramolecular H-bonding
(b) o-nitrophenol shows intermolecular H-bonding
(c) melting point of o-nitrophenol is lower than those of m-and p-isomers
(d) o-nitrophenol is more volatile in steam than those of m-and p-isomers.
Answer:

Question 16.
For the reaction C2H5OH + HX → C2H5X + H2O ; the order of reactivity is
(a) HCl>HBr>HI
(b) HI>HBr>HCl
(c) HBr > HCl > HI
(d) HI > HCl > HBr
Answer:
(b) HI>HBr>HCl

Question 17.
Which of the following is the prople method to prepare n-hexane from n-propyl alcohol ?
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 3
(a) (X) → HBr,(Y) → HCN
(b) (X) →HBr,(Y) → Na,ether
(c) (X) → Br2,(Y)→ CH3CN
(d) (X) →  Br2,(Y) → KMnO4
Answer:
(b) (X) →HBr,(Y) → Na,ether

Question 18.
Which of the following compounds does not react with NaOH?
(a) CH3COOH
(b) CH3CONH2
(c) C6H5OH
(d) CH3CH2OH
Answer:
(d) CH3CH2OH

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 19.
Out of 2-chloroethanol and ethanol which is more acidic and why ?
(a) 2-Chloroethanol due to +1 effect of Cl
(b) Ethanol due to +1 effect of CH3
(c) 2-Chloroethanol due to -1 effect of Cl
(d) Ethanol due to -1 effect of CH3
Answer:
(c) 2-Chloroethanol due to -1 effect of Cl

Question 20.
The correct sequence of decreasing acidity is
(a) (CH3)3COH > (CH3)2CHOH > C2H5OH > CH3OH
(b) CH3OH > C2H5OH > (CH3)2CHOH > (CH3)3COH
(c) C2H5OH > CH3OH > (CH3)3COH > (CH3)2CHOH
(d) (CH3)2CHOH > (CH3)3COH > C2H5OH >CH3OH
Answer:
(b) CH3OH > C2H5OH > (CH3)2CHOH > (CH3)3COH

Question 21.
Order of esterification of alcohols is
(a) 3°> 1°> 2°
(b) 2°>3°> 1°
(c) r>2°>3°
(d) none of these
Answer:
(c) r>2°>3°

Question 22.
Which of the following alcohols reacts most readily with Lucas reagent ?
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 4
Answer:
(c)

Question 23.
Tertiary butyl alcohol gives tertiary butyl chloride on treatment with
(a) HCl/anhydrous ZnCl2
(b) KCN
(c) NaOCl
(d) Cl2
Answer:
(a) HCl/anhydrous ZnCl2

Question 24.
R-OH + HX → RX + H2O
In the above reaction, the reactivity of alcohols is
(a) tertiary > secondary > primary
(b) tertiary < secondary < primary
(c) tertiary > primary > secondary
(d) secondary > primary > tertiary
Answer:
(a) tertiary > secondary > primary

Question 25.
Which of the following alcohols will give the most stable carbocation during dehydration ?
(a) 2-Methyl-1-propanol
(b) 2-Methyl-2-propanol
(c) 1-Butanol
(d) 2-Butanol
Answer:
(b) 2-Methyl-2-propanol

Question 26.
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 5 in the reaction X is,
(a) (CH3)2 C = CHCH3
(b) CH3C = CH
(c) (CH3)2CHCH2CH3
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 6
Answer:
(a) (CH3)2 C = CHCH3

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 27.
The major product of acid catalysed dehydration of 2- meyhylcyclohexanol and butan-l-ol are respectively
(a) 1-methylcyclohexene and but-l-ene
(b) 2-methylcyclohexene and but-2-ene
(c) 2-methylcyclohexene and butane
(d) 1-methylcyohexene and but-2-ene
Answer:
(a) 1-methylcyclohexene and but-l-ene

Question 28.
A compound X with the molecular formula C3H8O can be oxidised to another compound Y whose molecular formula is C3H6O2. The compound X may be
(a) CH3CH2OCH3
(b) CH3CH2CHO
(c) CH3CH2CH2OH
(d) CH3CHOCH3
Answer:
(c) CH3CH2CH2OH

Question 29.
The best reagent to convert pent-3-en-2-ol into pent-3- en-2-one is
(a) acidic permanganate
(b) acidic dichromate
(c) chromic anhydride in glacial acetic acid
(d) pyridinium chlorochromate
Answer:
(d) pyridinium chlorochromate

Question 30.
The most suitable reagnent for the conversion of RCH2OH → RCHO is
(a) K2Cr2O7
(b) CrO3
(c) KMnO4
(d) PCC
Answer:
(d) PCC

Question 31.
Conversion of ethyl alcohol into acetaldehyde is an example of
(a) hydrolysis
(b) oxidation
(c) reduction
(d) molecular rearrangement
Answer:
(b) oxidation

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 32.
Vapours of an alcohol X when passed over hot reduced copper, produce an alkene, the alcohol is
(a) primary alcohol
(b) secondary alcohol
(c) tertiary alcohol
(d) dihydric alcohol
Answer:
(c) tertiary alcohol

Question 33.
What happens when tertiary butyl alcohol is passed over heated copper at 300°C ?
(a) Secondary butyl alcohol is formed
(b) 2-Methylpropene is formed
(c) 1-Butene is formed
(d) Butanal is formed
Answer:
(b) 2-Methylpropene is formed

Question 34.
Which of the following reagents can not be used to oxidise 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
Answer:
(b) KMnO4 in acidic medium

Question 35.
Which of the following compounds will be most easily attacked by an electrophile ?
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 6
Answer:
(c)

Question 36.
Picric acid is a yellow coloured compound. Its chemical name is
(a) m-nitrobenzoic acid
(b) 2, 4, 6-trinitrophenol
(c) 2, 4, 6-tribromophenol
(d) p-nitrophenol
Answer:
(b) 2, 4, 6-trinitrophenol

Question 37.
Phenol when treated with excess of bromine water gives a white precipite of
(a) 2, 4, 6-tribromophenol
(b) o-bromophenol
(c) p-bromophenol
(d) bromobenzene
Answer:
(a) 2, 4, 6-tribromophenol

Question 38.
The major product obtained on interaction of phenol with sodium hydroxide and carbon dioxide is
(a) benzoic acid
(b) salicylaldehyde
(c) salicylic acid
(d) phthalic acid
Answer:
(c) salicylic acid

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 39.
The reaction between phenol and chloroform in the presence of aqueous NaOH is
(a) nucleophilic substitution reaction
(b) electrophilic addition reaction
(c) electrophilic substitution reaction
(d) nucleophilic addition reaction
Answer:
(c) electrophilic substitution reaction

Question 40.
Benzoquinone is prepared by reaction of phenol with
(a) Na2Cr2O7,H2SO4
(b) KMnO4,H2SO4
(c) NaCrO4,HCl
(d) K2MnO4,H2SO4
Answer:
(a) Na2Cr2O7,H2SO4

Question 41.
Consider the following reaction,
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 7
The product Z is
(a) benzaldehyde
(b) benzoic acid
(c) benzene
(d) toluene
Answer:
(b) benzoic acid

Question 42.
Methyl alcohol is industrially prepared by the action of
(a) CH3COCH3
(b) CO + H2
(c) CH3COOH
(d) C2H5OH
Answer:
(b) CO + H2

Question 43.
The enzyme which can catalyse the conversion of glucose to ethanol is
(a) inverstase
(b) zymase
(c) maltase
(d) diastase
Answer:
(b) zymase

Question 44.
An equimolar quantities of ethanol and propanol is heated with cone. H2SO4. The product formed is/are
(a) C2H5OC2H5
(b) C3H7OC3H7
(c) C2H5OC3H7
(d) all of these
Answer:
(d) all of these

Question 45.
Which of the following alcohols gives the best yield of dialkyl ether on being heated with a trace of sulphuric acid ?
(a) 2-Pentanol
(b) 2-Methyl-2-butanol
(c) 1-Pentanol
(d) 2-Propanol
Answer:
(c) 1-Pentanol

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 46.
Ether is obtained from ethyl alcohol in presence of.H2SO4 at
(a) 113 K
(b) 443 K
(c) 413K
(d) 213 K
Answer:
(c) 413K

Question 47.
Correct order of boiling points among following is
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 8
(a) X > Y > Z
(b) Y > X > Z
(c) Z > X > Y
(d) Z > Y > X
Answer:
(c)

Question 48.
Which of the following are the products shown by the reaction of methoxyethane with HI ?
(a) C2H5I + CH3OH
(b) CH3I + H2O
(c) C2H5OH + H2O
(d) C2H5OH+CH3I
Answer:
(d) C2H5OH+CH3I

Question 49.
Which of the following products are not correctly matched in the given reaction ?
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 9
Answer
(b)

Question 50.
The ether that undergoes electrophilic substitution reaction is
(a) CH3OC2H5
(b) C6H5OCH3
(c) CH3OCH3
(d) C2H5OC2H5
Answer:
(b) C6H5OCH3

Question 51.
Anisole on reaction with chloromethane in presence of anhydrous AlCl3 gives
(a) o-methyl aniosle and p-methoxy anisole
(b) p-methyl anisole and p-methoxy aniosle
(c) o-methyl anisole and p-methyl anisole
(d) o-methoxy acetophenone and p-methoxy acetophenone
Answer:
(c) o-methyl anisole and p-methyl anisole

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 52.
Monochlorination of toluene in sunlight followed by hydrolysis with aq. NaOH yields
(a) o-cresol
(b) m-cresol
(c) 2,4-dihydroxytoluene
(d) benzyl alcohol
Answer:
(d) benzyl alcohol

Question 53.
How many alcohols with molecular formula C4H10O are chiral in nature ?
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(a) 1

Question 54.
CH3CH2OH can be converted into CH3CHO by
(a) catalytic hydrogenation
(b) treatment with Li AlH4
(c) treatment with pyridinium chlorochromate
(d) treatment with KMnO4
Answer:
(c) treatment with pyridinium chlorochromate

Question 55.
The process of converting halides into alcohols involves
(a) addition reaction
(b) substitution reaction
(c) dehydrohalogenation reaction
(d) rearrangement reaction
Answer:
(b) substitution reaction

Question 56.
Give IUPAC name of the compound given below :
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 10
(a) 2-Chloro-5-hydroxyhexane
(b) 2-Hydroxy-5-chlorohexane
(c) 5-Chlorobexan-2-ol
(d) 2-Chlorohexan-5-ol
Answer:
(c) 5-Chlorobexan-2-ol

Question 57.
IUPAC name of m-cresol is
(a) 3-methylphenol
(b) 3-chlorophenol
(c) 3-methoxyphenol
(d) benzene-1,3-diol
Answer:
(a) 3-methylphenol

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 58.
IUPAC name of the compound
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 11
(a) 1-methoxy-1-methylethane
(b) 2-methoxy-2-methyIethane
(c) 2-methoxypropane
(d) isopropyl methyl ether
Answer:
(c) 2-methoxypropane

Question 59.
Which of the following species can act as the strongest base ?
(a) – OH
(b) – OR
(c) – OC6H5
(d)
Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers 12
Answer:
(b) – OR

Question 60.
Which of the following compounds will react with sodium hydroxide solution in water ?
(a) C6H5OH
(b) C6H5CH2OH
(c) (CH3)3COH
(d) C2H5OH
Answer:
(a) C6H5OH

Question 61.
Phenol is less acidic than
(a) ethanol
(b) o-nitrophenol
(c) o-methylphenol
(d) o-methoxphenol
Answer:
(b) o-nitrophenol

Bihar Board 12th Chemistry Objective Answers Chapter 11 Alcohols, Phenols and Ethers

Question 62.
Which of the following is most acidic ?
(a) Benzyl alcohol
(b) Cyclohexanol
(c) Phenol
(d) m-Chlorophenol
Answer:
(d) m-Chlorophenol