MnO4 HNO2 NO3 Mn2 Balance this by adding appropriate amount

MnO4^- +HNO2 --> NO3^- +Mn^2+

Balance this by adding appropriate amount of H2O, H+, e-

Solution

2MnO4^- + 5HNO2 + H+ --> 5NO3^- +2Mn^2+ + 3H2O