CBSE Class 12 Chemistry Alcohols Phenols and Ethers MCQs Set H

Question. Which statement is not correct about alcohol?
(a) Molecular weight of alcohol is higher than water
(b) Alcohol of less no. of carbon atoms is less soluble in water than alcohol of more no. of carbon atoms
(c) Alcohol evaporates quickly
(d) All of the above

Answer: b

Question. HBr reacts fastest with
(a) 2-Mehtylpropan-1-ol
(b) 2-Methylpropene-2-ol
(c) propan-2-ol
(d) propan-1-ol

Answer: b

Question. Phenol is more acidic than alcohol because
(a) phenol is more stable than water
(b) phenol is aromatic and alcohol is aliphatic
(c) phenoxide ion is resonance stabilised
(d) None of these

Answer: c

Question. Which of the following is correct ?
(a) On reduction of any aldehyde, secondary alcohol is formed
(b) Reaction of vegetable oil with H₂SO₄ gives glycerine
(c) Sucrose on reaction with NaCl gives invert sugar
(d) Alcoholic iodine gives iodoform with NaOH

Answer: d

Question. When ethyl alcohol reacts with acetic acid, the products formed are
(a) Sodium ethoxide + hydrogen
(b) Ethyl acetate + water
(c) Ethyl acetate + soap
(d) Ethyl alcohol + water

Answer: b

Question. The ionization constant of phenol is higher than that of ethanol because :
(a) phenoxide ion is bulkier than ethoxide
(b) phenoxide ion is stronger base than ethoxide
(c) phenoxide ion is stabilized through delocalization
(d) phenoxide ion is less stable than ethoxide

Answer: c

Question. To distinguish between salicylic acid and phenol, one can use
(a) NaHCO₃ solution
(b) 5% NaOH solution
(c) neutral FeCl₃
(d) bromine water

Answer: a

Question. n-Propyl alcohol and isopropyl alcohol can be chemically distinguished by which reagent?
(a) PCl₅
(b) Reduction
(c) Oxidation with potassium dichromate
(d) Ozonolysis

Answer: c

Question. Widespread deaths due to liquor poisoning occurs due to
(a) presence of carbonic acid in liquor
(b) presence of ethyl alcohol in liquor
(c) presence of methyl alcohol in liquor
(d) presence of lead compounds in liquor

Answer: c

Question. Which of the following compounds is oxidised to prepare methyl ethyl ketone?
(a) 2-Propanol
(b) l-Butanol
(c) 2-Butanol
(d) t-Butyl alcohol

Answer: c

Question. Acidity of phenol is due to
(a) hydrogen bonding
(b) phenolic group
(c) benzene ring
(d) resonance stabilisation of its anion

Answer: d

Question. Which of the following has lowest boiling point ?
(a) p-Nitrophenol
(b) m-Nitrophenol
(c) o-Nitrophenol
(d) Phenol

Answer: c

Question. Lucas test is done to differentiate between
(a) alcohol and ketone
(b) alcohol and aromatic ketones
(c) 1°, 2° and 3° alcohols
(d) None of these

Answer: c

Question. The compound which reacts fastest with Lucas reagent at room temperature is
(a) Butan-1-ol
(b) Butan-2-ol
(c) 2-Methyl propan-1-ol
(d) 2-Methylpropan-2-ol

Answer: d

Question. Which one of the following alcohols is least soluble in water?
(a) CH₃OH
(b) C₃H₇OH
(c) C₄H₉OH
(d) C₁₀H₂₁OH

Answer: d

Question. The correct order of boiling points for primary (1º), secondary (2º) and tertiary alcohol (3º) is
(a) 1º > 2º > 3º
(b) 3º > 2º > 1º
(c) 2º > 1º > 3º
(d) 2º > 3º > 1º

Answer: a

Question. ‘Drinking alcohol’ is very harmful and it ruins the health.
‘Drinking alcohol’ stands for
(a) drinking methyl alcohol
(b) drinking ethyl alcohol
(c) drinking propyl alcohol
(d) drinking isopropyl alcohol

Answer: b

Question. When phenol is treated with excess bromine water, it gives:
(a) m-Bromophenol
(b) o- and p-Bromophenol
(c) 2, 4-Dibromophenol
(d) 2, 4, 6-Tribromophenol

Answer: d

Question. Which of the following has strongest hydrogen bonding?
(a) Ethyl amine
(b) Ethanal
(c) Ethyl alcohol
(d) Diethyl ether

Answer: c

Question. Primary and secondary alcohols on action of reduced copper give
(a) Aldehydes and ketones respectively
(b) Ketones and aldehydes respectively
(c) Only aldehydes
(d) Only ketones

Answer: a

Question. Dehydration of 2-butanol yields
(a) 1-butene
(b) 2-butene
(c) 2-butyne
(d) Both (a) and (b)

Answer: d

Question. The ether that undergoes electrophilic substitution reactions is
(a) CH₃OC₂H₅
(b) C₆H₅OCH₃
(c) CH₃OCH₃
(d) C₂H₅OC₂H₅

Answer: b

Question. Phenols do not react with one of the following :
(a) Alkali metals
(b) Sodium hydroxide
(c) Potassium hydroxide
(d) Sodium bi-carbonate

Answer: d

Question. Which of the following is not true in case of reaction with heated copper at 300°C?
(a) Phenol → Benzyl alcohol
(b) Secondary alcohol → Ketone
(c) Primary alcohol → Aldehyde
(d) Tertiary alcohol → Olefin

Answer: a

Question. Oxygen atom in ether is
(a) very active
(b) replaceable
(c) comparatively inert
(d) active

Answer: c

Question. In the commercial manufacture of ethyl alcohol from starchy substances by fermentation method. Which enzymes slipwise complete the fermentation reaction
(a) Diastase, maltase and zymase
(b) Maltase, zymase and invertase
(c) Diastase, zymase and lactase
(d) Diastase, invertase and zymase

Answer: a

Question. Chemical name of salol is
(a) acetylsalicyclic acid
(b) sodium salicylate
(c) phenyl salicylate
(d) methyl salicylate

Answer: c

Question. Methanol and ethanol are miscible in water due to
(a) covalent character
(b) hydrogen bonding character
(c) oxygen bonding character
(d) None of these

Answer: b

Question. If ethanol dissolves in water, then which of the following would be observed
(a) absorption of heat and contraction in volume
(b) emission of heat and contraction in volume
(c) absorption of heat and increase in volume
(d) emission of heat and increase in volume

Answer: b

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

Answer: d

Question. On distilling phenol with Zn dust, one gets :
(a) Toluene
(b) Benzaldehyde + ZnO
(c) ZnO + benzene
(d) Benzoic acid

Answer: c

Question. Diethyl ether on heating with conc. HI gives two moles of
(a) ethanol
(b) iodoform
(c) ethyl iodide
(d) methyl iodide

Answer: b

Question. Ethyl alcohol exhibits acidic character on reacting it with
(a) acetic acid
(b) sodium metal
(c) hydrogen chloride
(d) acidic K₂Cr₂O₇

Answer: b

Question. An industrial method of preparation of methanol is :
(a) catalytic reduction of carbon monoxide in presence of ZnO–Cr₂O₃
(b) by reacting methane with steam at 900ºC with a nickel catalyst
(c) by reducing formaldehyde with lithium aluminium hydride
(d) by reacting formaldehyde with aqueous sodium hydroxide solution

Answer: a

Question. Commercially carboxylic acids are reduced to alcohols by converting them to the ______.
(a) esters
(b) aldehydes
(c) ketones
(d) amines

Answer: a

Question. Select the incorrect statement about the fermentation.
(a) When grapes are crushed, sugar and the enzyme come in contact and fermentation starts
(b) Fermentation takes place in anaerobic conditions
(c) Carbon monoxide is released during fermentation
(d) If air gets into fermentation mixture, the oxygen of air oxidises ethanol to ethanoic acid which in turn destroys the taste of alcoholic drinks

Answer: c

Question. The fermentation of starch to give alcohol occurs mainly with the help of
(a) O₂
(b) air
(c) CO₂
(d) enzymes

Answer: d