CHEMISTRY

JAMB 2003 - Question 46

Chemistry 2003 JAMB Past Questions - Question 46: Ethanol reacts with excess acidified K2Cr207 to produce

Choose the correct answers from the options given.
Ethanol reacts with excess acidified K2Cr207 to produce
A:
B:
C:
D:
Examkits App

Examkit's JAMB CBT App

Practice JAMB offline with our Online, PC and Mobile App

  • ✅ 25+ years of past questions (2000 to 2025)
  • ✅ Video solutions and explanation to questions
  • ✅ E-library
  • ✅ Study by topic
  • ✅ And more.

Correct Answer

D

Explanation

 When ethanol (C2H5OH) reacts with excess acidified potassium dichromate (K2Cr2O7), it undergoes oxidation. The reaction results in the formation of ethanoic acid (acetic acid, CH3COOH) and chromium(III) ions. The balanced chemical equation for this reaction is as follows:

\[ 3\text{C}_2\text{H}_5\text{OH} + 2\text{K}_2\text{Cr}_2\text{O}_7 + 16\text{HCl} \rightarrow 6\text{CH}_3\text{COOH} + 4\text{CrCl}_3 + 11\text{H}_2\text{O} + 4\text{KCl} \]

In this reaction, ethanol is oxidized to ethanoic acid, and the orange dichromate ions (\(\text{Cr}_2\text{O}_7^{2-}\)) are reduced to green chromium(III) ions (\(\text{Cr}^{3+}\)). The hydrogen ions (H+) from the acidified potassium dichromate play a crucial role in facilitating the oxidation of ethanol.