Understanding Kolbe's Electrolytic Method

Kolbe's electrolytic method is a chemical reaction used to synthesize symmetrical alkanes. It involves the electrolysis of sodium or potassium salts of carboxylic acids in an aqueous solution.

During the electrolysis process, the carboxylate anion ($\text{RCOO}^-$) migrates to the anode. At the anode, it loses an electron, undergoes decarboxylation (loses $\text{CO}_2$), and forms an alkyl radical ($\text{R}\cdot$). Two alkyl radicals then combine (couple) to form a symmetrical alkane ($\text{R-R}$).

The general reaction at the anode is:

$\text{RCOO}^- \rightarrow \text{RCOO}\cdot + \text{e}^-$

$\text{RCOO}\cdot \rightarrow \text{R}\cdot + \text{CO}_2$

$2\text{R}\cdot \rightarrow \text{R-R}$

The overall reaction is:

$2\text{RCOO}^- \text{M}^+ \xrightarrow{\text{Electrolysis}} \text{R-R} + 2\text{CO}_2 + 2\text{M}^+ + 2\text{e}^-$

where M is a metal ion like $\text{Na}^+$ or $\text{K}^+$.

Let's examine the given options:

• Option 1: $\text{CH}_3\text{COONa}$ (Sodium acetate)

  This is the sodium salt of acetic acid. It is a salt of a carboxylic acid where $\text{R} = \text{CH}_3$. Kolbe's electrolysis can be applied to sodium acetate. The electrolysis of sodium acetate yields ethane ($\text{CH}_3\text{CH}_3$).

  $2\text{CH}_3\text{COO}^- \text{Na}^+ \xrightarrow{\text{Electrolysis}} \text{CH}_3\text{CH}_3 + 2\text{CO}_2 + 2\text{NaOH}$

• Option 2: Represents $\text{CH}_3\text{CH}_2\text{COOK}$ (Potassium propanoate)

  This is the potassium salt of propanoic acid. It is a salt of a carboxylic acid where $\text{R} = \text{CH}_3\text{CH}_2$. Kolbe's electrolysis can be applied to potassium propanoate. The electrolysis of potassium propanoate yields butane ($\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3$).

  $2\text{CH}_3\text{CH}_2\text{COO}^- \text{K}^+ \xrightarrow{\text{Electrolysis}} \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3 + 2\text{CO}_2 + 2\text{KOH}$

• Option 3: Represents $\text{CH}_3\text{COOK}$ (Potassium acetate)

  This is the potassium salt of acetic acid. It is a salt of a carboxylic acid where $\text{R} = \text{CH}_3$. Kolbe's electrolysis can be applied to potassium acetate. The electrolysis of potassium acetate yields ethane ($\text{CH}_3\text{CH}_3$).

  $2\text{CH}_3\text{COO}^- \text{K}^+ \xrightarrow{\text{Electrolysis}} \text{CH}_3\text{CH}_3 + 2\text{CO}_2 + 2\text{KOH}$

As seen from the analysis above, Kolbe's electrolytic method can be applied to sodium acetate (Option 1), potassium propanoate (Option 2), and potassium acetate (Option 3). Therefore, the method is applicable to more than one of the substances listed in options 1, 2, and 3.