240г 220г x2 NaOH+H3PO4=Na3PO3+H2O

To balance the equation NaOH + H3PO4 = Na3PO3 + H2O, we need to ensure that the number of atoms of each element is the same on both sides of the equation.

Here's how we balance the equation:

NaOH + H3PO4 = Na3PO3 + H2O

To balance the sodium (Na) atoms, we need 3 sodium atoms on the product side. So, we put a coefficient of 3 in front of NaOH:

3NaOH + H3PO4 = Na3PO3 + H2O

Next, let's balance the phosphorus (P) atoms. There is only 1 phosphorus atom on the reactant side, so we put a coefficient of 3 in front of H3PO4 to balance it:

3NaOH + 3H3PO4 = Na3PO3 + H2O

Now, let's balance the hydrogen (H) atoms. There are 9 hydrogen atoms on the left side, so we need 9 hydrogen atoms on the right side. We achieve this by placing a coefficient of 9 in front of H2O:

3NaOH + 3H3PO4 = Na3PO3 + 9H2O

Finally, let's balance the oxygen (O) atoms. There are 6 oxygen atoms on the left side (3 from NaOH and 3 from H3PO4), so we need 6 oxygen atoms on the right side. We can achieve this by placing a coefficient of 3 in front of Na3PO3:

3NaOH + 3H3PO4 = 3Na3PO3 + 9H2O

This is the balanced equation:

3NaOH + 3H3PO4 = 3Na3PO3 + 9H2O