An organic compound (A) with molecular formula $C2H4O$ is readily oxidized to a carboxylic acid (B) with molecular formula $C2H4O2$. Compound (A) on treatment with dilute NaOH gives compound (C), which on heating undergoes dehydration to give compound (D). Identify (A), (B), (C), and (D). Write the chemical equations for all the reactions involved.

Q: An organic compound (A) with molecular formula $C2H4O$ is readily oxidized to a carboxylic acid (B) with molecular formula $C2H4O2$. Compound (A) on treatment with dilute NaOH gives compound (C), which on heating undergoes dehydration to give compound (D). Identify (A), (B), (C), and (D). Write the chemical equations for all the reactions involved.

Step-by-Step Solution and Identification Identification of Compound (A): The molecular formula of compound (A) is $C2H4O$. This corresponds to acetaldehyde (ethanal), $CH3CHO$. Identification of Compound (B): Compound (A) ($CH3CHO$) on oxidation readily gives a carboxylic acid with formula $C2H4O2$, which is acetic acid (ethanoic acid), $CH3COOH$. Identification of Compound (C): When compound (A) ($CH3CHO$) is treated with dilute NaOH, it undergoes Aldol condensation to form 3-hydroxybutanal (compound C). Equation: $$2CH3CHO \xrightarrow{\text{dil. NaOH}} CH3-CH(OH)-CH2-CHO$$ Identification of Compound (D): Compound (C) (3-hydroxybutanal) on heating undergoes dehydration (loss of a water molecule) to yield but-2-enal (compound D). Equation: $$CH3-CH(OH)-CH2-CHO \xrightarrow{\Delta} CH3-CH=CH-CHO + H2O$$ Summary of Compounds: (A): Ethanal ($CH3CHO$) (B): Ethanoic acid ($CH3COOH$) (C): 3-Hydroxybutanal ($CH3CH(OH)CH2CHO$) (D): But-2-enal ($CH3CH=CHCHO$)

Question

Accepted Answer

Step-by-Step Solution and Identification

Identification of Compound (A):
- The molecular formula of compound (A) is $C_2H_4O$. This corresponds to acetaldehyde (ethanal), $CH_3CHO$.
Identification of Compound (B):
- Compound (A) ($CH_3CHO$) on oxidation readily gives a carboxylic acid with formula $C_2H_4O_2$, which is acetic acid (ethanoic acid), $CH_3COOH$.
Identification of Compound (C):
- When compound (A) ($CH_3CHO$) is treated with dilute NaOH, it undergoes Aldol condensation to form 3-hydroxybutanal (compound C).
- Equation: $$2CH_3CHO \xrightarrow{\text{dil. NaOH}} CH_3-CH(OH)-CH_2-CHO$$
Identification of Compound (D):
- Compound (C) (3-hydroxybutanal) on heating undergoes dehydration (loss of a water molecule) to yield but-2-enal (compound D).
- Equation: $$CH_3-CH(OH)-CH_2-CHO \xrightarrow{\Delta} CH_3-CH=CH-CHO + H_2O$$

Summary of Compounds:

(A): Ethanal ($CH_3CHO$)
(B): Ethanoic acid ($CH_3COOH$)
(C): 3-Hydroxybutanal ($CH_3CH(OH)CH_2CHO$)
(D): But-2-enal ($CH_3CH=CHCHO$)