Carbonyl compounds

Select carbonyl compounds from the following formulae:

• C₄H₁₀O
• C₄H₈O
• C₄H₈O₂
• C₄H₈

The name of this compound is:

• heptan-2-one
• 2-hexanone
• 2-heptanone
• pentan-2-one

Which of the following alcohols can be oxidised to 2-methyl-3-pentanone?

• CH₃CH₂CH(OH)CH₃

• CH₃CH(OH)CH₂CH₂CH₃

• (CH₃)₃CCH(OH)CH₃

• (CH₃)₂CHCH(OH)CH₂CH₃

The following reaction scheme shows how propene can be prepared from propanal in two stages using reagents X and Y. Which of the following are the reagents X and Y?

X Y

CH₃CH₂CHO → CH₃CH₂CH₂OH → H₃CH=CH₂

• X: LiAlH₄ ; Y: KOH, ethanol, reflux

• X: NaBH₄ ; Y: conc.H₂SO₄, heat

• X: dillute H₂SO₄ ; Y: conc.ethanol, reflux

• X: dillute H₂SO₄ ; Y: KOH, ethanol, reflux

On heating compound X with acidified KMnO₄, compound Y is obtained. Compound Y does not react with Fehling’s solution. X and Y are most likely to be,

Compound X Compound Y

• CH₃COCH₃ CH₃COOH

• CH₃CH(OH)CH₃ CH₃COCH₃

• CH₃CH₂CH₂OH CH₃COCH₃

• CH₃CH₂CH₂OH CH₃CH₂CHO

Acetone reacts with HCN to form a cyanohydrin. It is an example of

• Electrophilic addition

• Electrophilic substituition

• Nucleophilic addition

• Nucleophilic substituition

Which reagent would you choose to convert 1-pentanol to pentanal?

• PCC in CH₂Cl₂

• K₂Cr₂O₇ with aqueous H₂SO₄

• KMnO₄ with aqueous H₂SO₄

• KOH, ethanol, reflux

When aldehyde is heated with Fehling's solution, it gives a precipitate of

• Cu₂O

• CuO

• Cu₂O & CuO

• Cu

Aldehyde reacts with Tollen's reagent forming:

• Yellow precipitate
• Brick-red precipitate
• Purple solution
• Silver mirror

1. Iodoform test: Yellow precipitate

2. Tollens' test: No observable change

3. 2,4-DNPH: yellow precipitate

Which compound will have the above observations?

• CH₃CH₂CHO

• C₆H₅CHO

• CH₃CH₂COCH₃

• CH₃COOH