Organic Chemistry MCQ with Answers

126) The most reactive compound towards formation of cyanohydrin on treatment with KCN followed by acidification is:

Answer is:

p−nitrobenzaldehyde

Explanation:

Due to electron withdrawing nature of NO₂ group, the partial positive charge on the carbon atom of the C=O group in p−nitrobenzaldehyde increases and becomes more susceptible to nucleophilic attack by CN⁻ group.

127) The smallest ketone and its next homologue are reacted with NH₂OH to form oxime then:

Answer is:

Three different oximes are formed

128) m−chlorobenzaldehyde on reaction with conc. KOH at room temperature gives:

Answer is:

Potassium m−chlorobenzoate and m−chlorobenzyl alcohol

129) A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives:

Answer is:

Benzyl alcohol and sodium formate

Explanation:

It is a cross−Cannizaro reaction.

130) Which of the following on heating with aqueous KOH produces acetaldehyde?

Answer is:

126) The most reactive compound towards formation of cyanohydrin on treatment with KCN followed by acidification is:

p−nitrobenzaldehyde

127) The smallest ketone and its next homologue are reacted with NH2OH to form oxime then:

Three different oximes are formed

128) m−chlorobenzaldehyde on reaction with conc. KOH at room temperature gives:

Potassium m−chlorobenzoate and m−chlorobenzyl alcohol

129) A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives:

Benzyl alcohol and sodium formate

130) Which of the following on heating with aqueous KOH produces acetaldehyde?

CH3CHCl2

127) The smallest ketone and its next homologue are reacted with NH₂OH to form oxime then:

CH₃CHCl₂