One mole of `N_(2)H_(4)` loses ten moles of electrons to form a new compound `A`. Assuming that all the nitrogen appears in the new compound, what is the oxidation state of nitrogen in `A`? (There is no change in the oxidation state of hydrogen.)

Explanation

`N_(2)H_(4) rarr Y + 10 e^(-)` ,O.S. of N in `N_(2)H_(4) : 2x + 4 = 0 implies x = -2` The two nitrogen atoms will balance the charge of 10e
Hence oxidation state of N will increase by +5 , i.e. from -2 to +3