Consider the following reactions for nitrification shown below:

$2N{H}_4^{+}+3O_{2}2N{O}_2^{-}+4H^{+}+2H_{2}O$

$2N{O}_2^{-}+O_{2}2N{O}_3^{-}$

A$.$ Determine the overall reaction by combining the two reactions and simplifying.

B$.$ Consider a $1-$liter sample of water with no alkalinity and with $10m\frac{g}{L}N{H}_4^{+}-N($note$,$ this means $m\frac{g}{L}$ as $N,$ so use a molecular weight of $14\frac{g}{m}ol$ of $N{H}_4^{+}$instead of $18\frac{g}{m}ol.$ Assuming the water had a $pH$ of $7$ before the reaction starts, what will the $pH$ be after all $10mg$ of $N{H}_4^{+}-N$ are oxidized to $N{O}_3^{-?}$

C$.$ How many mg of oxygen would be consumed if all $10mg$ of $N{H}_4^{+}-N$ are oxidized to $N{O}_3^{-}?$