Question

One type of breathalyzer employs a fuel cell to measure the quantity of alcohol in the breath. When a suspect blows into the breathalyzer, ethyl alcohol is oxidized to acetic acid at the anode: CH3CH2OH(g)+4OH?(aq)?HC2H3O2(g)+3H2O(l)+4e? At the cathode, oxygen is reduced: O2(g)+2H2O(l)+4e??4OH?(aq) The overall reaction is the oxidation of ethyl alcohol to acetic acid and water. When a suspected drunk driver blows 188 mL of his breath through this breathalyzer, the breathalyzer produces an average of 327 mA of current for 10 s.