Q15 / 75 · JEE Main 2026 (06 April Shift 1) · Chemistry
Given below are two statements:
Statement I: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of sodium acetate and reaction of $\text{CH}_3\text{MgBr}$ with water.
Statement II: Methane cannot be prepared from unsaturated hydrocarbons and by Wurtz reaction.
In the light of the above statements, choose the correct answer from the options given below
Statement I: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of sodium acetate and reaction of $\text{CH}_3\text{MgBr}$ with water.
Statement II: Methane cannot be prepared from unsaturated hydrocarbons and by Wurtz reaction.
In the light of the above statements, choose the correct answer from the options given below
- ABoth Statement I and Statement II are true
- BBoth Statement I and Statement II are false
- CStatement I is true but Statement II is false
- Correct answerDStatement I is false but Statement II is true
Solution
Statement I is false because Kolbe's electrolysis of sodium acetate produces ethane, not methane. The reaction is: $2\text{CH}_3\text{COONa} + 2\text{H}_2\text{O} \xrightarrow{\text{Electrolysis}} \text{CH}_3-\text{CH}_3 + 2\text{CO}_2 + \text{H}_2 + 2\text{NaOH}$. Decarboxylation of sodium ethanoate and the reaction of $\text{CH}_3\text{MgBr}$ with water do produce methane.
Statement II is true because the simplest unsaturated hydrocarbon is ethene ($\text{C}_2\text{H}_4$), which upon hydrogenation yields ethane, meaning methane cannot be prepared from unsaturated hydrocarbons. Additionally, the Wurtz reaction involves the coupling of two alkyl halide molecules to form an alkane with at least two carbon atoms ($2\text{RX} + 2\text{Na} \rightarrow \text{R}-\text{R} + 2\text{NaX}$), so methane cannot be prepared by this method.
Therefore, Statement I is false but Statement II is true.
Answer: Statement I is false but Statement II is true
Statement II is true because the simplest unsaturated hydrocarbon is ethene ($\text{C}_2\text{H}_4$), which upon hydrogenation yields ethane, meaning methane cannot be prepared from unsaturated hydrocarbons. Additionally, the Wurtz reaction involves the coupling of two alkyl halide molecules to form an alkane with at least two carbon atoms ($2\text{RX} + 2\text{Na} \rightarrow \text{R}-\text{R} + 2\text{NaX}$), so methane cannot be prepared by this method.
Therefore, Statement I is false but Statement II is true.
Answer: Statement I is false but Statement II is true
Hence, the correct answer is option: 'D'.