Question

What is the coefficient for `H^+` when the redox equation below is balanced?

`?Ag(s) + ?NO_3^(-)(aq) + ?H^(+)(aq) -> ?Ag^(+)(aq) + ?NO(g) + ?H_2O`

Answer 1

`3Ag(s) +NO_3^(-) +4H^(+)rarr 3Ag^(+) +NO +2H_2O`

Explanation:

As usual we write separate redox reactions:

`"Oxidation:"`

`Ag(s) rarr Ag^(+) + e^-` `(i)`

`"Reduction:"`

`NO_3^(-) +4H^(+) + 3e^(-) rarr NO +2H_2O` `(ii)`

And so, we add `3xx(i) + (ii):`

`3Ag(s) +NO_3^(-) +4H^(+)rarr 3Ag^(+) +NO +2H_2O`

This is balanced with respect to mass and charge, so it is reasonable.

The nitrate anion is in fact a potent oxidant; however, in aqueous solution, often its reactivity is kinetically hindered.