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 12 of 34
- A. Alkanol
- B. Alkanal
- C. Alkanone
- D. Alkyl halides
Explanation: The IUPAC names of ketones are derived from the names of alkanes having the same number of carbon atoms.
Correct answer: Alkanone- A. One Carboxylic acid
- B. Mixture of different carboxylic acids
- C. Same type of carboxylic acids
- D. None of these
Explanation: When symmetrical ketones undergo oxidation, they typically yield a mixture of different carboxylic acids.
Correct answer: Mixture of different carboxylic acids- A. Ketones
- B. Aldehydes
- C. Ethers
- D. Alkyl halides
Explanation: Chemically, an 'aldehyde' is a compound containing a functional group with the structure −CHO, consisting of a carbonyl center (a carbon…
Correct answer: Aldehydes- A. Acetaldehyde
- B. Acetone
- C. Carboxylic acid
- D. Alkene
- E. Both C and D
Explanation: NaBH4 is a weak reducing agent. It can reduce aldehydes, ketones and acid chlorides but not carboxylic acids and double bonds (alkenes).
Correct answer: Both C and D- A. K2Cr2O7
- B. HNO3
- C. Tollen's reagent
- D. All of these
Explanation: Aldehyhdes have the general formula of CnH2n+2CHO. It is to be kept in mind that all aldhyde have CHO group at the terminal carbon.
Correct answer: All of these- A. CH3I
- B. CHI3
- C. CH2I2
- D. CI4
Explanation: Iodoform is a yellow solid compound with the formula CHI3. It is a halogenoform, a type of organic compound that contains iodine.
Correct answer: CHI3- A. Secondary alcohols
- B. Tertiary alcohols
- C. Dihydric alcohols
- D. Primary alcohols
Explanation: Aldehydes can be obtained by the oxidation of primary alcohols. Primary alcohols, when oxidized, are first converted into aldehydes.
Correct answer: Primary alcohols- A. CuO
- B. RCOONa
- C. Cu2O
- D. Cu(OH)2
Explanation: Option C is correct as Benedict's solution tests to find reducing agents which reduce copper citrate (blue solution) to "copper(I)oxide or…
Correct answer: Cu2O- A. Trigonal
- B. Linear
- C. Tetrahedral
- D. Square planer
Explanation: The correct geometry of acetal is C) Tetrahedral. Acetal has a tetrahedral arrangement of atoms around the central carbon atom, with two…
Correct answer: Tetrahedral- A. Tollen's test
- B. Reaction with hydrazine
- C. Reaction with 2,4-dinitrophenylhydrazine
- D. Reaction with Ammonia
Explanation: Option C is correct as "2,4-DNPH" reacts with aldehydes and ketones to give a orange precipitate by reacting with the carbonyl group.
Correct answer: Reaction with 2,4-dinitrophenylhydrazine- A. Hydroxyl ion
- B. Carbocation
- C. Carbanion
- D. Water
Explanation: Option C: The 1st step in the mechanism of aldol condensation is removal of a proton from an alpha carbon of aldehyde/ketone by base, thus…
Correct answer: Carbanion- A. Acetal
- B. Ketal
- C. Carboxylic acid
- D. Alcohol
Explanation: The product formed when alcohol is added to acetaldehyde is acetal. Acetal is a type of organic compound that is formed by the reaction of…
Correct answer: Acetal- A. Aldehydes
- B. Methanol
- C. Primary alcohols
- D. Secondary alcohols
Explanation: Option D is correct since the reduction of ketones produces secondary alcohols.
Correct answer: Secondary alcohols- A. Elimination + addition
- B. Elimination + substitution
- C. Addition + substitution
- D. None of these
Explanation: Option A is correct since condensation reactions involve the elimination of small molecules in the form of water or HCl.
Correct answer: Elimination + addition- A. Pharmalin
- B. Paraldehyde
- C. Formamint
- D. Formalin
Explanation: Formaldehyde (HCHO) is a colorless gas with a pungent odor. It is used in a variety of industrial processes and is also used as a…
Correct answer: Formalin- A. Carbonyl carbon
- B. Carbon attached to smaller number of hydrogen atom
- C. Carbon attach to larger number of hydrogen atoms
- D. Hydrogen
Explanation: The oxidation of unsymmetrical ketones involves the cleavage of the carbon-carbon bond adjacent to the carbonyl group.
Correct answer: Carbon attached to smaller number of hydrogen atom- A. Aldehyde
- B. Alcohol
- C. Both A and B
- D. Ketone
Explanation: The aldol reaction involves the formation of a beta-hydroxy carbonyl compound through the addition of an enolate ion (generated from an…
Correct answer: Both A and B- A. Aldol product
- B. Alcohol and carboxylate salt
- C. Alcohol and carboxylic acid
- D. Unsaturated reaction
Explanation: Option B is correct since, in Cannizzaro's reaction, alcohol (reduced product) and salt of carboxylic acid (oxidized product) are formed.
Correct answer: Alcohol and carboxylate salt- A. Aldehyde is given priority
- B. Aldehyde is parent
- C. Aldehyde group is present at terminal
- D. None of these
Explanation: Aldehyde group is given position 1 and does not have its position mentioned because it is always present at the terminal end of the carbon…
Correct answer: Aldehyde group is present at terminal- A. Mixed
- B. Unsymmetrical
- C. Symmetrical
- D. None of these options are correct
Explanation: If both alkyl groups attached to the carbonyl group in a ketone are the same, it is called "symmetrical."For example, in acetone…
Correct answer: Symmetrical