1. Identify the reagent which is used to check the presence of an aldehyde or a keto group in an organic compound.
(A) 
(B)
(c)
(D)
Ans D
Explain :2,4 – Dinitrophenylhydrazine reacts with aldehydes or ketones to form yellow, orange, or reddish-orange precipitates.
2. Aldehydes react with one equivalent of monohydric alcohols in the presence of dry hydrogen chloride to give
(a) An acetal
(b) An oxime
(c) A hemiacetal
(d) A ketal
Ans (c) A hemiacetal
3. C6H5COOC2H5 on acid catalysed hydrolysis produces
(a) Benzoic acid + Ethanol
(b) Ethanoic acid + Phenol
(c) Benzoic acid + ethanoic acid
(d) Ethanoic acid + Benzene
Ans (a) Benzoic acid + Ethanol
4. Which simple chemical test is used to distinguish between ethanal and propanal?
(a) Iodoform test
(b) Fehling’s test
(c) Tollen’s test
(d) Lucas test
Ans (a) Iodoform test
5. Out of following given compounds, identify which carbonyl compound gives aldol reaction?
(a) 
(b) 
(c) 
(d) 
Ans C
Aldehydes having α-hydrogens give aldol reaction e.g. CH3CHO
6. The IUPAC name of the given compound
(a) 2-Methylbutoxybenzene
(b) 3-Methylbutoxybenzene
(c) 3- Methylphenoxybenzene
(d) 2- Methyl-4-Phenoxybutane
Ans (b) 3-Methylbutoxybenzene
7. Which one of the following product is NOT formed when mixture of ethanal and propanal heated with dil. NaOH?
(a) But-2-enal
(b) Pent-3-enal
(c) 2-Methylpent-2-enal
(d) 2-Methylbut-2-enal
Ans (b) Pent-3-enal
Explain. When aldol condensation is carried out between two different aldehydes / ketones, it is called cross aldol condensation. If both of them contain α-hydrogen atoms, it gives a mixture of four products.
8. Pentan-2-one and pentan-3-one can be distinguished by
(a) Iodoform test
(b) Neutral FeCl3 test
(c) Blue litmus test
(d) Lucas reagent test
Ans (a) Iodoform test
9. Which aldehyde is used to preserve biological specimens?
(a) Acetaldehyde
(b) Butanal
(c) Benzaldehyde
(d) Formaldehyde
Ans (d) Formaldehyde
Explain : Formaldehyde is will known as formalin (40%) solution used to preserve biological specimens.
10. Write the correct IUPAC name of the compound given below
(a) 2-Oxopentanoic acid
(b) 4-Formylpentanoic acid
(c) 4-Oxopentanoic acid
(d) 4-Onepentanoic acid
Ans (c) 4-Oxopentanoic acid
11. Samples of benzaldehyde and acetaldehyde can be distinguished by using
(a) 2,4 Dinitrophenylhydrazine
(b) Tollen’s reagent
(c) Mixture of Fehling solution A + B
(d) Zn-Hg/HCl
Ans (c) Mixture of Fehling solution A + B
Explain : Acetaldehyde gives positive Fehling’s test while benzaldehyde does not respond to the Fehling’s reagent.
12. Correct IUPAC name of
(a) Pent-2-enal
(b) Pent-2-enol
(c) pent-3-enal
(d) pent-3-enol
Ans (a) Pent-2-enal