# How do you write a equation for "Aluminum + copper (ll) sulfate -> copper + aluminum sulfate"?

Dec 23, 2015

$2 A l \left(s\right) + 3 C u S {O}_{4} \left(a q\right) \to A {l}_{2} {\left(S {O}_{4}\right)}_{3} \left(a q\right) + 3 C u \left(s\right)$

#### Explanation:

The reaction would be the following :

$2 A l \left(s\right) + 3 C u S {O}_{4} \left(a q\right) \to A {l}_{2} {\left(S {O}_{4}\right)}_{3} \left(a q\right) + 3 C u \left(s\right)$

This is an oxidation-reduction reaction were electrons are transferred from Aluminum $A l$ which get oxidized to Copper $C {u}^{2 +}$ which gets reduced.

Oxidation: $A l \left(s\right) \to A {l}^{3 +} \left(a q\right) + 3 {e}^{-}$

Reduction: $C {u}^{2 +} \left(a q\right) + 2 {e}^{-} \to C u \left(s\right)$

The net redox reaction would then be:

$\textcolor{red}{2 \times} \left(A l \left(s\right) \to A {l}^{3 +} \left(a q\right) + \cancel{3 {e}^{-}}\right)$
$\textcolor{red}{3 \times} \left(C {u}^{2 +} \left(a q\right) + \cancel{2 {e}^{-}} \to C u \left(s\right)\right)$
$- - - - - - - - - - - - - - -$
$2 A l \left(s\right) + 3 C {u}^{2 +} \left(a q\right) \to 2 A {l}^{3 +} \left(a q\right) + 3 C u \left(s\right)$

Note that $S {O}_{4}^{2 -}$ is a spectator ion.