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Answer the following.
From the organic compounds given below: I. Acetophenone II. Benzaldehyde III. Benzophenone Arrange…
From the organic compounds given below:
I. Acetophenone
II. Benzaldehyde
III. Benzophenone
(a)[1.0]
Arrange the compounds in the decreasing order of reactivity towards addition of HCN.
(b)[1.0]
Give a chemical reaction when compound I is treated with compound II in the presence of a dilute alkali.
Answer
Answer (a)
Official answer keyOrder, first to last: Benzaldehyde, Acetophenone, Benzophenone
II > I > III
Answer (b)
Official answer keyEquation: $\mathrm{C_{6}H_{5}CHO} + \mathrm{C_{6}H_{5}COCH_{3}} \xrightarrow{\text{dil.}\text{ }\text{OH-}} \mathrm{C_{6}H_{5}CH(OH)CH_{2}COC_{6}H_{5}}$
Reaction: Crossed aldol (Claisen-Schmidt) condensation
Product: 3-hydroxy-1,3-diphenylpropan-1-one
Crossed aldol (Claisen-Schmidt) condensation: benzaldehyde and acetophenone with dilute alkali give $\mathrm{C_6H_5CH(OH)CH_2COC_6H_5}$ (3-hydroxy-1,3-diphenylpropan-1-one).
From ISC 2025 Practice Chemistry, question 52.