# Question #9d279

Nov 9, 2017

So, from that notation, we may assume nickel is being reduced and chromium is being oxidized. Furthermore, there is mathematical proof since nickel's reduction potential is more positive than chromium's (in this case).

Reduction: $N {i}^{2 +} + 2 {e}^{-} \to N i \left(s\right)$
Oxidation: $C r \left(s\right) \to C {r}^{3 +} + 3 {e}^{-}$

In order to balance the reaction for a net reaction, the coefficients for electrons must agree. Hence,

$\left[N {i}^{2 +} + 2 {e}^{-} \to N i \left(s\right)\right] \cdot 3$
$\left[C r \left(s\right) \to C {r}^{3 +} + 3 {e}^{-}\right] \cdot 2$
$- - - - - - - - - -$
$3 N {i}^{2 +} \left(a q\right) + 2 C r \left(s\right) r i g h t \le f t h a r p \infty n s 3 N i \left(s\right) + 2 C {r}^{3 +} \left(a q\right)$