Free Alcohols MCQs with Answers
154 Alcohols 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 contain a hydroxyl group attached to a saturated carbon atom and are classified as primary, secondary or tertiary. Their nomenclature, hydrogen bonding, acidity, oxidation, dehydration, reaction with sodium and conversion to haloalkanes are covered, along with the distinction between alcohols and phenols, where the hydroxyl group is attached directly to an aromatic ring.
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154 questions · page 3 of 8
- A. primary alcohol
- B. secondary alcohol
- C. tertiary alcohol
- D. dihydric alcohol
Explanation: A Grignard reagent opens ethylene oxide and adds its organic group to the ring; acid hydrolysis then converts the magnesium alkoxide into…
Correct answer: primary alcohol- A. formaldehyde
- B. ketone
- C. ethylene epoxide
- D. both A & C
Explanation: Formaldehyde reacts with a Grignard reagent to give a primary alcohol after hydrolysis, and ethylene oxide also gives a primary alcohol…
Correct answer: both A & C- A. formaldehyde
- B. acetaldehyde
- C. propanone
- D. carbondioxide
Explanation: Formaldehyde and aldehydes or ketones react with Grignard reagents to form alcohols after hydrolysis, but CO2 gives a magnesium…
Correct answer: carbondioxide- A. primary alcohol
- B. secondary alcohol
- C. tertiary alcohol
- D. dihydric alcohol
Explanation: Ethyl magnesium bromide adds an ethyl group to acetone, converting the carbonyl carbon into a carbon bonded to three carbon groups and an…
Correct answer: tertiary alcohol- A. ketone
- B. Aldehyde
- C. Alkene then - COOH
- D. Ester
Explanation: A primary alcohol is oxidized first to an aldehyde under controlled conditions, while further oxidation can produce a carboxylic acid.
Correct answer: Aldehyde- A. methylated spirit
- B. wood spirit
- C. rectified spirit
- D. absolute alcohol
Explanation: Ethanol containing about 5% water, or approximately 95% ethanol by volume, is called rectified spirit and cannot be completely purified by…
Correct answer: rectified spirit- A. 12% alcohol
- B. 90% alcohol
- C. 95% alcohol
- D. 100% alcohol
Explanation: Rectified spirit is ethanol purified by fractional distillation to about 95% alcohol by volume, with the remaining water forming an…
Correct answer: 95% alcohol- A. a solvent
- B. an anti freezing agent
- C. a substitute for petrol
- D. for denaturing of ethyl alcohol
Explanation: Methanol is widely used as a solvent, antifreeze, and denaturant for ethanol because it makes alcohol unsuitable for drinking.
Correct answer: a substitute for petrol- A. NaBH4
- B. HBr
- C. Na2Cr2O7
- D. Grignard reagent
Explanation: When an ether is treated with HBr, it undergoes an acid-catalyzed cleavage reaction to form an alcohol and an alkyl halide.
Correct answer: HBr- A. 2-Ethanoic acid
- B. 2-Ethanoate
- C. Diethyl ether
- D. Ethanol
Explanation: Ethanol can be oxidized to produce acetaldehyde, which is an aldehyde. The oxidation can be carried out using an oxidizing agent such as…
Correct answer: Ethanol- A. CH2 - CH2 - OH
- B. OH|CH3 - CH - CH3
- C. CH3|CH3 - CH2 - C - OH|CH3
Explanation: Tertiary alcohols do not undergo oxidation with potassium dichromate and sulfuric acid to form alkenes.
Correct answer: CH3|CH3 - CH2 - C - OH|CH3- A. Formaldehyde
- B. Acetaldehyde
- C. Methanol
- D. Ethanol
Explanation: Formaldehyde (CHO): When ethane-1,2-diol undergoes oxidative cleavage, it forms two molecules of formaldehyde.
Correct answer: Formaldehyde- A. 1-Butanol
- B. 2-Butanol
- C. 2-Methyl-2- Propanol
- D. 1- Propanol
Explanation: Melting and boiling points of alcohols are higher than corresponding alkanes.
Correct answer: 1-Butanol- A. Lucas test
- B. Benedict test
- C. Toulen test
Explanation: The iodoform test is a chemical test used to identify the presence of methyl ketones or secondary alcohols containing a methyl group…
Correct answer: Toulen test- A. CH3-OH
- B. CH3-CH2 OH
Explanation: The order of reactivity if alcohols with respect to O-H bond cleavage is:CH3OH> Primary alcohol> Secondary alcohol> Tertiary alcohol
Correct answer: CH3-OH- A. Helium gas
- B. Hydrogen gas
- C. Carbon dioxide
- D. Carbon monoxide
Explanation: Option b is the correct answer. The reaction of alcohols with sodium metal results in the formation of hydrogen gas.
Correct answer: Hydrogen gas- A. Methanol
- B. Ethanol
- C. 2-Propanol
- D. 2-Methyl 2-Propanol
Explanation: 2-Methyl-2-propanol will produce the least stable alkoxide ion among the options.
Correct answer: 2-Methyl 2-Propanol- A. Ethanol
- B. Isobutyl alcohol
- C. Propanol
- D. Methanol
Explanation: Methanol cannot be synthesized directly from the reaction of a Grignard reagent with an aldehyde or ketone.
Correct answer: Methanol- A. C3H8
- B. C2H5COOH
- C. C3H7OH
- D. (CH3)2CO
Explanation: Primary alcohol like option C can be oxidized to aldehyde and thus can reduce the substance oxidizing it.
Correct answer: C3H7OH- A. Conc. H2SO4
- B. CaO
- C. Al2O3
- D. H3PO4
Explanation: The explanation for this question will be added soon!
Correct answer: CaO