e) None of the above 3. Balance each redox reaction occurring in acidic aqueous solution. K(s) + _Cr" (aq) _Cr(s) + _K (aq) a b. Al(s)+ _Fe*(aq) _Al (aq) + Fe(s) Cou (COM 4. [Balancing a redox equation] The following redox reaction is used in acidic solution in the Breathalyzer test to determine the level of alcohol in the blood: H(aq) + _Cr0,- (aq) + _C.H.OH(aq) -- _Cr" (aq) + _C.H.O(aq) + _H2O(1) Fill in the blank