240г 220г x2 NaOH+H3PO4=Na3PO3+H2O

To balance the equation NaOH + H3PO4 = Na3PO4 + H2O, we need to make sure that there is an equal number of atoms of each element in the reactants and products.

NaOH + H3PO4 = Na3PO4 + H2O

First, let's balance the phosphorus (P) atoms. There are 3 in H3PO4 and only 1 in Na3PO4, so we need to multiply Na3PO4 by 3 to balance the phosphorus:

NaOH + H3PO4 = 3Na3PO4 + H2O

Next, let's balance the sodium (Na) atoms. There is 1 in NaOH and 3 in 3Na3PO4, so we need to multiply NaOH by 3 as well:

3NaOH + H3PO4 = 3Na3PO4 + H2O

Now let's balance the hydrogen (H) atoms. There are 3 in H3PO4 and 2 in H2O, so we need to multiply H2O by 3 to balance the hydrogen:

3NaOH + H3PO4 = 3Na3PO4 + 3H2O

Finally, let's balance the oxygen (O) atoms. There are 1 in NaOH, 4 in H3PO4, and 3 in 3Na3PO4, so we need to multiply NaOH by 4 and H3PO4 by 3:

12NaOH + 4H3PO4 = 3Na3PO4 + 3H2O

Therefore, the balanced equation is:

12NaOH + 4H3PO4 = 3Na3PO4 + 3H2O