# Question #76b1a

Feb 5, 2015

The oxidation numbers for each atom in AgCN are Ag: +1 C: +2 N: -3

#### Explanation:

The easiest way to see what oxidation numbers to assign to each atom in silver cyanide is to look at the compound from the perspective of ions.

Here, you're dealing with the cyanide anion, or ${\text{CN}}^{-}$, which automatically implies that the silver cation must have a $\text{+1}$ charge $\to$ ${\text{Ag}}^{+}$.

Now look at the cyanide ion. You know that the more electronegative atom must have the negative charge, and that the ion's overall charge is $\text{(-1)}$. If you look in the periodic table, you'll that nitrogen is in group 15, which means it needs 3 more electrons to complete its octet.

If you give nitrogen a $\text{-3}$ oxidation number, carbon will be left with a $\text{+2}$ oxidation state, which is in accordance with the fact that nitrogen is more electronegative than carbon and thus must have the negative charge.

Therefore, the oxidation numbers for each atom in $\text{AgCN}$ are

$\text{Ag: +1}$
$\text{C: +2}$
$\text{N: -3}$