Calculate the masses of 10% sodium hydroxide solution and 15% phosphoric acid solution

Calculate the masses of 10% sodium hydroxide solution and 15% phosphoric acid solution required to obtain 82 g of sodium phosphate.

1. Let us write down the reaction equation for sodium phosphate production:

3NaOH + H3PO4 = Na3PO4 + 3H2O;

2. calculate the chemical quantities:

n (Na3PO4) = m (Na3PO4): M (Na3PO4);

M (Na3PO4) = 3 * 23 + 31 + 4 * 16 = 164 g / mol;

n (Na3PO4) = 82: 164 = 0.5 mol;

n (NaOH) = n (Na3PO4) * 3 = 0.5 * 3 = 1.5 mol;

n (H3PO4) = n (Na3PO4) = 0.5 mol;

3.Calculate the mass of sodium hydroxide:

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

M (NaOH) = 23 + 17 = 40 g / mol;

m (NaOH) = 1.5 * 40 = 60 g;

4. find the mass of phosphoric acid:

m (H3PO4) = n (H3PO4) * M (H3PO4);

M (H3PO4) = 3 + 31 + 4 * 16 = 98 g / mol;

m (H3PO4) = 0.5 * 98 = 49 g;

5.determine the masses of acid and alkali solutions:

m (solution H3PO4) = m (H3PO4): w (H3PO4) = 49: 0.15 = 326.67 g;

m (NaOH solution) = m (NaOH): w (NaOH) = 60: 0.1 = 600 g.

Answer: 600 g of NaOH solution, 326.67 g of H3PO4 solution.