You are given the reaction Cu + HNO3 Cu (NO3) 2 + NO + H2O. Which element is oxidized? Which element is reduced?

The element which is oxidized and reduced in the equation below is

Cu + HNO3 = CU (NO3) 2 + NO + H2O

Cu is been oxidized while HNo3 is reduced

Cu is oxidized because it move from oxidation state zero to oxidation state of positive two (2^+). HNO3 act as the oxidizing agent therefore it oxidizes Cu while itself is reduced by Cu