One type of alcohol breathalyzers used by law enforcement involves the following reaction. The amount of ethanol present is determined by a change in color of the solution. What type of reaction is this? 3CH₃CH₂OH(g) + 2K₂Cr₂O₇(aq) + 8H₂SO₄(aq) $\rightarrow$
3CH₃COOH(aq) + 2Cr₂(SO₄) ₃(aq) + 2K₂SO₄(aq) + 11H₂O

Question

One type of alcohol breathalyzers used by law enforcement involves the following reaction. The amount of ethanol present is determined by a change in color of the solution. What type of reaction is this? 3CH₃CH₂OH(g) + 2K₂Cr₂O₇(aq) + 8H₂SO₄(aq)

\rightarrow

3CH₃COOH(aq) + 2Cr₂(SO₄) ₃(aq) + 2K₂SO₄(aq) + 11H₂O

Quizplus · Accepted Answer

This is an oxidation-reduction reaction because ethanol (CH3CH2OH) is being oxidized to form acetic acid (CH3COOH) and chromium (VI) is being reduced to chromium (III). The change in color of the solution indicates the amount of chromium (VI) ions present, which is proportional to the amount of ethanol in the sample.

One Type of Alcohol Breathalyzers Used by Law Enforcement Involves →\rightarrow→

One Type of Alcohol Breathalyzers Used by Law Enforcement Involves $\rightarrow$