Acidic Hydrolysis of Enol Ether Molecule X and Identification of Statement Properties

To determine the correct statements regarding compounds $(Y)$ and $(Z)$, we first analyze the structure of molecule $(X)$ and its reaction under mild acidic conditions.

1. Acidic Hydrolysis of Molecule $(X)$

Molecule $(X)$ is an unsymmetrical divinyl ether with the chemical structure: $\text{CH}_3-\text{CH}=\text{CH}-\text{O}-\text{C}(\text{CH}_3)=\text{CH}_2$

Under mild acidic hydrolysis, the ether linkage undergoes cleavage to form two enols: $\text{CH}_3-\text{CH}=\text{CH}-\text{O}-\text{C}(\text{CH}_3)=\text{CH}_2 + \text{H}_2\text{O} \xrightarrow{\text{H}^+} \text{CH}_3-\text{CH}=\text{CH}-\text{OH} + \text{CH}_2=\text{C}(\text{OH})-\text{CH}_3$

These enols immediately undergo tautomerization to yield their corresponding carbonyl compounds:

• $\text{CH}_3-\text{CH}=\text{CH}-\text{OH} \rightleftharpoons \text{CH}_3-\text{CH}_2-\text{CHO}$ (Propanal)
• $\text{CH}_2=\text{C}(\text{OH})-\text{CH}_3 \rightleftharpoons \text{CH}_3-\text{CO}-\text{CH}_3$ (Propan-2-one / Acetone)

Thus, the products $(Y)$ and $(Z)$ are propanal and acetone.

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2. Analysis of the Given Statements

• Statement A: Both $(Y)$ and $(Z)$ have same molar mass.

  • Both propanal ($\text{CH}_3\text{CH}_2\text{CHO}$) and acetone ($\text{CH}_3\text{COCH}_3$) share the same molecular formula, $\text{C}_3\text{H}_6\text{O}$.
  • Their molar mass is identical: $\text{Molar Mass} = 3 \times 12 + 6 \times 1 + 16 = 58 \text{ g mol}^{-1}$
  • Statement A is CORRECT.

• Statement B: $(Y)$ and $(Z)$ can be distinguished from each other by $\text{NaHCO}_3$.

  • Sodium bicarbonate ($\text{NaHCO}_3$) reacts with carboxylic acids and strong acids to liberate $\text{CO}_2$ gas, but it does not react with either aldehydes or ketones.
  • Hence, neither propanal nor acetone reacts with $\text{NaHCO}_3$, making it impossible to distinguish them using this test.
  • Statement B is INCORRECT.

• Statement C: $(Y)$ and $(Z)$ react with $\text{HCN}$ with same rates.

  • Nucleophilic addition of $\text{HCN}$ depends on steric hindrance and the electrophilicity of the carbonyl carbon.
  • Aldehydes (propanal) have less steric hindrance and a more electrophilic carbonyl carbon than ketones (acetone), making propanal react significantly faster with $\text{HCN}$ than acetone.
  • Statement C is INCORRECT.

• Statement D: $(Y)$ and $(Z)$ undergo addition reaction with 2,4-DNP.

  • Both aldehydes and ketones contain the active carbonyl group ($>\text{C}=\text{O}$) and react with 2,4-dinitrophenylhydrazine (2,4-DNP) via nucleophilic addition followed by elimination to form colored 2,4-dinitrophenylhydrazone precipitates.
  • Statement D is CORRECT.

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Conclusion

The correct statements are A and D Only.

Correct Answer: D