Free Aldehydes and Ketones MCQs with Answers
679 Aldehydes and Ketones MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.
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679 questions · page 23 of 34
- A. Ethyl alcohol
- B. 2-Hydroxypropanoic acid
- C. Methyl cyanide
- D. Ethyl cyanide
Explanation: When acetaldehyde and HCN react, they form an addition compound called cyanohydrin.
Correct answer: 2-Hydroxypropanoic acid- A. I2/NaOH
- B. LiAIH4
- C. Benedict's reagent
- D. sodium nitroprusside
Explanation: The reagent used to distinguish between ethanal and propanal is 1/2 NaOH, which stands for half molar concentration of sodium hydroxide.
Correct answer: I2/NaOH- A. Acetone
- B. Acetaldehyde
- C. Ethanol
- D. Formaldehyde
Explanation: Acetaldehyde gives a positive haloform test and a positive Fehling solution test.
Correct answer: Acetaldehyde- A. HCOOH
- B. CH3CHO
- C. C2H5OH
- D. HCHO
Explanation: When calcium formate and calcium acetate are dry heated, they do not directly form CH3CHO (acetaldehyde).
Correct answer: CH3CHO- A. Phenyl hydrazine
- B. Hydrazine
- C. Hydroxylamine
- D. Hydrogen cyanid
Explanation: All others form addition elimination product.when acetaldehyde or ketones react with hydrogen cyanide, something cool happens.
Correct answer: Hydrogen cyanid- A. Fehling test
- B. Benedict test
- C. Ninhydrin test
- D. Tollen's test
Explanation: The reaction you mentioned is actually the Tollens test. It's a chemical test that helps us detect the presence of aldehydes.
Correct answer: Tollen's test- A. Acetone
- B. Acetic acid
- C. Dimethyl ether
- D. Acetaltdehyde
Explanation: If not distilled, aldehyde will be oxidized to corresponding carboxylic acid.So, when the student mixed ethyl alcohol with sodium…
Correct answer: Acetaltdehyde- A. Fehling's solution test
- B. Iodoform test
- C. Tollen's reagent test
- D. Benedict's solution test
Explanation: The silver mirror test is a chemical test used to detect the presence of aldehydes in a given sample.
Correct answer: Tollen's reagent test- A. π-bond of C and O
- B. Sigma bond of C and H
- C. Sigma bond of C and O
- D. sigma of C and C
Explanation: when we talk about the pi bond between the carbon (C) and oxygen (O) atoms in aldehydes and ketones, it's a bit "wonky" or distorted.
Correct answer: π-bond of C and O- A. Silver mirror test
- B. Fehling's solution test
- C. 2, 4 DNPH test
- D. Benedict's solution test
Explanation: Both aldehydes and ketones give a positive result in the 2,4-DNP test. This test involves adding a solution of 2,4-dinitrophenylhydrazine…
Correct answer: 2, 4 DNPH test- A. NaCO3
- B. NaBH4
- C. Al
- D. Red P
Explanation: When it comes to converting a ketone to a secondary alcohol, sodium borohydride (NaBH4) is the reagent you're looking for.
Correct answer: NaBH4- A. Methanol
- B. Methyl ketone
- C. 3- Hexanol
- D. Propionaldehyde
Explanation: The iodoform test is a way to detect the presence of a methyl ketone. In this test, we mix the methyl ketone (a ketone with a methyl group…
Correct answer: Methyl ketone- A. Propionaldehyde
- B. Propanal
- C. Propanone
- D. Butanal
Explanation: When you oxidize 2-propanol, it undergoes a chemical reaction that results in the formation of propoanone, which is also called acetone.
Correct answer: Propanone- A. Aldehyde
- B. Alkyl halide
- C. Ketone
- D. Ester
Explanation: When you oxidize a secondary alcohol, like 2-propanol, it undergoes a chemical reaction that results in the formation of a ketone.
Correct answer: Ketone- A. Oxidation of C2H5OH
- B. Formation of C2H5NH2
- C. Reduction of C2H5OH
- D. Dissolution of CO2
Explanation: When wine is exposed to air, it can become sour due to a process called oxidation.
Correct answer: Oxidation of C2H5OH- A. Addition reaction
- B. C - H bond cleavage
- C. Elimination reaction
- D. Combustion reaction
Explanation: The conversion of tertiary alcohols into alkenes in the presence of K2Cr2O7 and H2SO4 is indeed an elimination reaction.
Correct answer: Elimination reaction- A. Acetaldehyde
- B. Acetone
- C. propanal
- D. Propanoic acid
Explanation: When 1-propanol undergoes oxidation in the presence of H2SO4 and K2Cr2O7, the final product that is formed is propanoic acid.
Correct answer: Propanoic acid- A. CH3C(CH3)2OH
- B. CH3CH2CH2OH
- C. (CH3)3COH
- D. (CH3)2CHOH
Explanation: Primary alcohols produce aldehydes upon oxidation.When CH3CH2CH2OH, which is 1-propanol, is treated with K2Cr2O7/H2SO4, it undergoes…
Correct answer: CH3CH2CH2OH- A. Aldehyde
- B. Ketone
- C. Carboxylic Acid
- D. Alcohol
Explanation: When 2-propanol undergoes oxidation, it gives us a ketone as the final product.
Correct answer: Ketone- A. Propan-2øl
- B. Butan-2øl
- C. Butan-1øl
- D. 2me thyl Butan-2øl
Explanation: When butan-2-ol undergoes oxidation, it gives us ethyl methyl ketones as the final product.
Correct answer: Butan-2øl