CBSE Class 12 · 2011 · All India · Aldehydes Ketones and Carboxylic AcidsLong Answer

WhatsApp Email

i) Illustrate the following name reactions:
a) Cannizzaro reaction b) Clemmensen reduction
ii) How would you obtain the following?
a) but-2-enal from ethanal b) butanoic acid from butanol c) benzoic acid from ethylbenzene

Answer: (i) Standard equations. (ii)(a) Aldol + Δ; (b) K₂Cr₂O₇/H₂SO₄; (c) KMnO₄/OH⁻, Δ then H⁺.

Solution

(i)(a)

2HCHO conc.NaOH C H_{3} OH + HCOONa

(b)

C_{6} H_{5} COC H_{3} Zn (Hg) /HCl C_{6} H_{5} C_{2} H_{5}

(ii)(a)

2C H_{3} CHO dil.NaOH C H_{3} CH (OH) C H_{2} CHO Δ C H_{3} CH = CHCHO

(b)

C_{4} H_{9} OH K_{2} C r_{2} O_{7} / H_{2} S O_{4} C_{3} H_{7} COOH

(c)

C_{6} H_{5} C_{2} H_{5} KMn O_{4} /O H^{-}, Δ H^{+} C_{6} H_{5} COOH

CBSE Class 12 Board · 2011 · All India · Subjective

Practise more: all CBSE board PYQs on Aldehydes Ketones and Carboxylic Acids →

More board questions on Aldehydes Ketones and Carboxylic Acids

Draw the structure of the major product of the reaction shown in the figure (part a).
CBSE 2024View solution →
(a) An organic compound (A) with the molecular formula C₉H₁₀O forms a 2,4-DNP derivative, reduces Fehling solution and undergoes Cannizzaro reaction. On vigorous oxidation it gives benzene-1,2-dicarboxylic acid.
(i) Identify compound (A) and write its IUPAC name.
(ii) Write the r …
CBSE 2024View solution →
(b)(i) Account for the following:
(1) The alpha (α) hydrogens of aldehydes and ketones are acidic in nature.
(2) Oxidation of aldehydes is easier than that of ketones.
(ii) Arrange the following:
(1) decreasing reactivity towards nucleophilic addition: propanal, acetone, benzalde …
CBSE 2024View solution →
Which one of the following has the lowest pKₐ value?
CBSE 2023View solution →
Assertion (A): Bromination of benzoic acid gives m-bromobenzoic acid.
Reason (R): The carboxyl group increases the electron density at the meta position.
CBSE 2023View solution →
(a)(i) Write the reaction involved in Cannizzaro's reaction.
(ii) Why are the boiling points of aldehydes and ketones lower than those of the corresponding carboxylic acids?
(iii) An organic compound 'A' with molecular formula C₅H₈O₂ is reduced to n-pentane with hydrazine followe …
CBSE 2023View solution →