A ‘breath test’ used by traffic police to check drunken driving uses?

A. Tumeric on filter paper
B. Silica gel coated with saliva nitrate
C. Potassium permanganate-sulphuric acid
D. Potassium dichromatic-sulphuric acid

Correct Answer:

Option D – Potassium dichromatic-sulphuric acid

Explanation

The earliest developed breathalyzer was based on reaction of alcohol if present in the exhaled air with a cocktail of chemicals containing sulfuric acid, potassium dichromate, silver nitrate, and water. Silver nitrate catalyzes the reaction between alcohol and potassium dichromate in acidic medium.