Give reasons : (a) Propanone is less reactive than ethanal towards nucleophilic addition reactions. (b) O_(2)N -CH_(2) -COOH has lower pKa value than CH_(3)COOH ( c) (CH_(3))_(2)CH-CHO undergoes aldol condensation whereas (CH_(3))_(3)C-CHO does not.

Give reasons : (a) Propanone is less reactive than ethanal towards nu

1.	Give reasons : (a) Propanone is less reactive than ethanal towards nucleophilic addition reactions. (b) O_(2)N -CH_(2) -COOH has lower pKa value than CH_(3)COOH ( c) (CH_(3))_(2)CH-CHO undergoes aldol condensation whereas (CH_(3))_(3)C-CHO does not.
Answer» Solution :(a) Propanone is less reactive than ethanal towards nucleophilic addition reaction due to (i) STERIC hindrance (ii) + I effect of two alkyl groups in propanone. (b) - `-NO_(2)`exerts electron withdrawing effect which increases the acidic STRENGTH or decreases the `pK_(a)`VALUE. (c) Aldol condensation reaction is given by substances which have at LEAST one alpha hydrogen atom. `(CH_3)_2CH — CHO` has an a-hydrogen atom but `(CH_3)_3C — CHO` does not have `alpha` -hydrogen atom.