Question

(ii) What happens when (write chemical equation only):
\begin{enumerate} \item Ethanol is heated with \(\text{K}_2\text{Cr}_2\text{O}_7\) and concentrated sulphuric acid? \item Ethyl alcohol is heated with glacial acetic acid in presence of conc. \(\text{H}_2\text{SO}_4\)? \item Acetic acid reacts with sodium bicarbonate? \end{enumerate}

Hint:

In organic reactions: 1. Potassium dichromate and sulfuric acid oxidize ethanol to acetic acid. 2. Glacial acetic acid with ethanol in the presence of sulfuric acid forms ethyl acetate (ester). 3. Acetic acid reacts with sodium bicarbonate to release carbon dioxide.

Answer 1

1. Ethanol is heated with K_2\text{Cr}_2\text{O}_7 and concentrated sulfuric acid:}
When ethanol is heated with potassium dichromate (\(K_2Cr_2O_7\)) in the presence of concentrated sulfuric acid (\(H_2SO_4\)), it gets oxidized to acetic acid (\(CH_3COOH\)): \[ \text{C}_2\text{H}_5\text{OH} + K_2\text{Cr}_2\text{O}_7 + H_2SO_4 \rightarrow \text{CH}_3\text{COOH} + Cr}_2\text{(SO}_4)_3 + H_2O \] 2. Ethyl alcohol is heated with glacial acetic acid in the presence of conc. \(H_2SO_4\):
When ethyl alcohol (ethanol) is heated with glacial acetic acid in the presence of concentrated sulfuric acid, esterification takes place, forming ethyl acetate (an ester): \[ \text{C}_2\text{H}_5\text{OH} + \text{CH}_3\text{COOH} \xrightarrow{\text{conc. } H_2SO_4} \text{CH}_3\text{COOC}_2\text{H}_5 + H_2O \] 3. Acetic acid reacts with sodium bicarbonate:
When acetic acid reacts with sodium bicarbonate (\(NaHCO_3\)), carbon dioxide gas (\(CO_2\)) is released, and sodium acetate (\(CH_3COONa\)) is formed: \[ \text{CH}_3\text{COOH} + \text{NaHCO}_3 \rightarrow \text{CH}_3\text{COONa} + \text{CO}_2 + H_2O \]