What mass of water is formed by the interaction of 40 g of sodium hydroxide with phosphoric acid?

1. Let’s write the equation of interaction of sodium hydroxide with phosphoric acid:

3NaOH + H3PO4 = Na3PO4 + 3H2O;

2.Calculate the chemical amount of sodium hydroxide:

n (NaOH) = m (NaOH): M (NaOH);

M (NaOH) = 23 + 16 + 1 = 40 g / mol;

n (NaOH) = 40: 40 = 1 mol;

3. Determine the amount of water formed:

n (H2O) = n (NaOH) = 1 mol;

4.calculate the mass of water:

m (H2O) = n (H2O) * M (H2O) = 1 * 18 = 18 g.

Answer: 18 g.