Free Alcohols and Phenols MCQs with Answers
535 Alcohols and Phenols MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alcohols are classified as primary, secondary or tertiary and studied through their hydrogen bonding, acidity, oxidation and reactions with active metals, acids and halogenating agents. Phenols require separate treatment because the hydroxyl group is attached to an aromatic ring, making their acidity and electrophilic substitution different from ordinary alcohols.
Last updated
Read the Alcohols and Phenols notesFree MDCAT chapter notes with key terms535 questions · page 6 of 27
- A. CH3OH
- B. C2H5OH
- C. C3H7OH
- D. C4H9OH
Explanation: Lower alcohols are generally colourless toxic liquids with characteristic sweet smell and burning taste They are readily soluble in water…
Correct answer: C4H9OH- A. Methylated spirit
- B. Rectified spirit
- C. Power alcoho
- D. Absolute alcohol
Explanation: Alcohol obtained by fermentation is only upto 12% and never exceeds 14% because beyond this limit enzymes become inactive.
Correct answer: Absolute alcohol- A. 1-butene-4-ol
- B. 2-butene-1-ol
- C. 3-butene-1-ol
- D. None of these
Explanation: The unsaturated alcohols are numbered in such a way that hydroxyl group rather than the point of unsaturation gets the lower number.
Correct answer: 3-butene-1-ol- A. Ethanol and formaldehyde
- B. Phenol and ethanol
- C. Phenol and formaldehyde
- D. Phenol and acetaldehyde
Explanation: Phenol reacts with formaldehyde (methanal) in the presence of acid or alkali to give hydroxy benzyl alcohol which on further reaction with…
Correct answer: Phenol and formaldehyde- A. C2H6
- B. C2H5Cl
- C. CH3 − O − CH3
- D. C2H5OH
Explanation: Melting and boiling points of alcohols are higher than corresponding alkanes.
Correct answer: C2H6- A. Pentanol
- B. 3-pentanone
- C. 2-pentanone
- D. Pentanoic acid
Explanation: Oxidation of alcohols convert them into aldehydes and ketones. The best reagent for this purpose is acid dichromate.
Correct answer: 2-pentanone- A. Methanal
- B. Methoxy methane
- C. Phenol
- D. Benzoic acid
Explanation: 1.Methanal has a formyl group in which carbon is doubly bonded to oxygen hence unsaturation is present.2.Methoxy methane has an ether…
Correct answer: Methoxy methane- A. Dehydration
- B. Hydration
- C. Hydrogenation
- D. Fermentation
Explanation: Alcohols react with con. H2SO4 and give different products at different temperatures.
Correct answer: Dehydration- A. CO2 gas
- B. H2 gas
- C. CO gas
- D. Steam
Explanation: Ethanol reacts with sodium metal to produce sodium ethoxide and release one mole of hydrogen gas.
Correct answer: H2 gas- A. HI
- B. NaOH
- C. Water
- D. KMnO4
Explanation: Ethers are comparatively inert substances. The reagents like ammonia, alkalies, dilute acids and metallic sodium, have no action on ethers…
Correct answer: HI- A. Diastase
- B. Zymase
- C. Urease
- D. Invertase
Explanation: Enzymes involved in fermentation are: diastase, maltase, zymase. Urease is not used in fermentation.
Correct answer: Urease- A. Acid
- B. Base
- C. Acid as well as a base
- D. None of these
Explanation: Ethers serve as Lewis bases. For instance, diethyl ether forms a complex with boron trifluoride, i.e. borane diethyl etherate
Correct answer: Base- A. CH3COCH3
- B. CH3COOCH3
- C. CH3CH2CHO
- D. CH3CH2COOH
Explanation: Option A is a ketone, and its reduction (NaBH4 is a reducing agent) results in a secondary alcohol.
Correct answer: CH3COCH3- A. Ethanol
- B. Butane
- C. Methanol
- D. Phenol
Explanation: Phenols occur as white solids at room temperature and may be highly toxic and caustic.
Correct answer: Phenol- A. 2,4 - DNPH test
- B. Tollens test
- C. Lucas Test
- D. Fehling solution test
Explanation: The Lucas test is used to differentiate primary, secondary, and tertiary alcohols.
Correct answer: Lucas Test- A. It is a colorless, volatile, thin liquid with specific gravity 0.796 at 15°C.
- B. It is used for low-temperature thermometers and as a fuel substitute.
- C. It is extensively used in the formation of different beverages.
- D. It is used as a base for perfumes.
- E. It is used as an antiseptic and disinfectant.
Explanation: Methyl Alcohol, also known as methanol, is a colorless, volatile, and thin liquid with a specific gravity of 0.796 at 15°C.
Correct answer: It is a colorless, volatile, thin liquid with specific gravity 0.796 at 15°C.- A. C2H5Cl and C2H5OC2H5
- B. C2H6 and C2H5OC2H5
- C. C2H5Cl and C2H5NO2
- D. C2H6 and C2H5NO2
- E. C2H6 and C2H6NO
Explanation: The sequence of reactions begins with ethanol (C2H5OH) reacting with phosphorus pentachloride (PCl5), resulting in the formation of ethyl…
Correct answer: C2H5Cl and C2H5NO2- A. Ethene
- B. Ethane
- C. Ethyne
- D. Ether
Explanation: Dehydration of alcohol at 140°C gives etherreference # ftb 162
Correct answer: Ether- A. Acid
- B. Ester
- C. Alcohol
- D. Aldehyde
Explanation: Phenol reacts with acetyl chloride (CH₃COCl) by acylation. The -OH group of phenol is converted into an ester linkage.
Correct answer: Ester- A. Methyl alcohol
- B. Ethyl alcohol
- C. Acetyl alcohol
- D. Methanal
Explanation: Starch essentially breaks down to give glucose which undergoes the process of glycolysis to give pyruvate and NADH alongside ATP.
Correct answer: Ethyl alcohol