Cola contains H3PO4. In order to determine the concentration of phosphoric acid in 50.0 mL of cola, a precipitation reaction with excess silver nitrate was carried out. The product, silver phosphate, was dried and found to weigh 0.0576g. What is the concentration of phosphoric acid in the cola?

Answer 1

0.0576 g Ag3PO4 = how many moles.
moles = g/molar mass.

1 mol Ag3PO4 contains how many moles of PO4^-3?

1 mol PO4^-3 is equivalent to how many H3PO4 moles?

Convert moles H3PO4 to grams and divide by 50 mL to obtain g H3PO4/mL or multiply that by 100 to convert to %.