Balancing reactions continued...

Here is the same reaction

Ba(NO₃)₂ + Na₂SO₄ → NaNO₃ + BaSO₄

Left side	Right side
Ba = 1	Ba = 1
NO3 = 2	NO3 = 1
Na = 2	Na = 1
SO4 = 1	SO4 = 1

The reaction is not balanced because there are different numbers of nitrates and sodium atoms.

We are NOT allowed to alter the formulas for the compounds. In other words we cannot change the Na₂SO₄ into NaSO₄ so, instead, we need to add coefficients.

One good way to start is to begin at the left. The first thing we run into is Ba, however barium is balanced (1 on each side). The next thing we run into is nitrate. This is unbalanced (2 on the left and only 1 on the right). So, I need another nitrate on the right, but remember, I cannot change the formula, so I'll add a coefficient of 2 in front of the sodium nitrate.

Ba(NO₃)₂ + Na₂SO₄ → 2 NaNO₃ + BaSO₄

Now if I count again:

Left side	Right side
Ba = 1	Ba = 1
NO3 = 2	NO3 = 2
Na = 2	Na = 2
SO4 = 1	SO4 = 1

As you can see, everything is balanced, so we're done.

Let's try another example