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Question: Answered & Verified by Expert
Assertion: Change in colour of acidic solution of potassium dichromate by breath is used to test drunken drivers.
Reason : Change in colour is due to complexation of alcohol with potassium dichromate.
Chemistryd and f Block ElementsAIIMSAIIMS 2015
Options:
  • A If both assertion and reason are true and reason is the correct explanation of assertion.
  • B Ifboth assertion and reason are true but reason is not the correct explanation of assertion.
  • C If assertion is true but reason is false.
  • D If both assertion and reason are false.
Solution:
2398 Upvotes Verified Answer
The correct answer is: If assertion is true but reason is false.
Acidified $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ (orange in colour) solution oxidises alcohol and itself gets reduced to $\mathrm{Cr}_2\left(\mathrm{SO}_4\right)_3$ which is green in colour.

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