# How do you balance "Ni(NO"_3)_2 + "NaOH"rarr"Ni(OH)"_2 + "NaNO"_3"?

Oct 12, 2016

$\text{Ni(NO"_3)_2+"2NaOH}$$\rightarrow$$\text{Ni(OH)"_2"+2NaNO"_3}$

#### Explanation:

Equation

$\text{Ni(NO"_3)_2+"NaOH}$$\rightarrow$$\text{Ni(OH)"_2"+NaNO"_3}$

First look for polyatomic ions . You can usually treat them as individual units.

There are two polyatomic ions in the equation. One is the nitrate anion, $\text{NO"_3^(-)}$, and the other is the hydroxide ion, $\text{OH"^(-)}$.

When balancing a chemical equation, you may only change the amount of each substance by adding coefficients in front of the formula. You may not change subscripts .

There are two nitrate ions on the left side of the equation and only one on the right side. Add a coefficient of 2 in front of the formula for $\text{NaNO"_3}$.

$\text{Ni(NO"_3)_2+"NaOH}$$\rightarrow$${\text{Ni(OH)"_2+color(red)("2")"NaNO}}_{3}$

There is one hydroxide ion on the left side and two on the right side.
Add a coefficient of $2$ in front of sodium hydroxide, $\text{NaOH}$.

$\text{Ni(NO"_3)_2+color(green)("2")"NaOH}$$\rightarrow$${\text{Ni(OH)"_2+color(red)("2")"NaNO}}_{3}$

Now there is one nickel ion on both sides of the equation, two sodium ions on both sides, two nitrate ions on both sides, and two hydroxide ions on both sides.