Assertion: Change in colour of acidic solution of potassium dichromate by breath is used to test drunken…
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.
If both assertion and reason are true and reason is the correct explanation of assertion.
Ifboth assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Solution
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.