How do copper and magnesium metals react with nitric acid?

Aug 26, 2017

Well, magnesium and zinc are quite active metals.........

Explanation:

And so.....

$M g \left(s\right) + 2 H N {O}_{3} \left(a q\right) \rightarrow M g {\left(N {O}_{3}\right)}_{2} \left(a q\right) + {H}_{2} \left(g\right) \uparrow$

$Z n \left(s\right) + 2 H N {O}_{3} \left(a q\right) \rightarrow Z n {\left(N {O}_{3}\right)}_{2} \left(a q\right) + {H}_{2} \left(g\right) \uparrow$

That is the metals are active enuff to reduce hydrogen ion to dihydrogen.

On the other hand... copper is a little bit less active.

Copper metal is oxidized to $C {u}^{2 +}$:

$C u \rightarrow C {u}^{2 +} + 2 {e}^{-}$

And nitrate is REDUCED to $N {O}_{2}$ if the nitric acid is concentrated...

$N {O}_{3}^{-} + 2 {H}^{+} + {e}^{-} \rightarrow N {O}_{2} \left(g\right) \uparrow + {H}_{2} O$

And so the overall equation.....

$C u \left(s\right) + 4 H N {O}_{3} \left(a q\right) \rightarrow C u {\left(N {O}_{3}\right)}_{2} \left(a q\right) + 2 N {O}_{2} \left(g\right) \uparrow + 2 {H}_{2} O \left(l\right)$