WAEC - Chemistry (2024 - No. 9)
The product of the reaction between ethanol and excess acidified K\(_2\)Cr\(_2\)O\(_7\) is
CH\(_2\)=CH\(_2\)
CH\(_3\)OCH\(_3\)
CH\(_3\)COOH
CH\(_3\)CH\(_3\)
Vysvětlení
When ethanol reacts with excess acidified potassium dichromate (K\(_2\)Cr\(_2\)O\(_7\)), it gets oxidized to ethanoic acid (acetic acid), with the color of the solution changing from orange to green as the chromium ions are reduced during the oxidation process; this reaction is a common test for alcohols due to the visible color change.
CH\(_3\)CH\(_2\)OH + K\(_2\)Cr\(_2\)O\(_7\) → CH\(_3\)COOH