How to solve for the mass of potassium phosphate produced from 2.45 mol of potassium hydroxide

Question

For the chemical reaction

3KOH+H3PO4⟶K3PO4+3H2O3KOH+H3⁢PO4⟶K3⁢PO4+3⁢H2O

what mass of potassium phosphate is produced from 2.45 mol of potassium hydroxide?

Answer 1

Hi Elizabeth,

To solve this problem, let's look at what the chemical reaction is telling us.

3 KOH + H₃PO₄ ⟶ K₃PO₄

The coefficients tell us the molar ratios of reactants and products. So 3 moles of KOH and 1 mole of H₃PO₄ will react to produce 1 mole of K₃PO₄. In this scenario, we only have 2.45 moles of KOH, so we will need to account for that while still maintaining the ratio of 3 mole KOH to 1 mole K₃PO₄.

1 mol K₃PO₄

2.45 mol KOH • 3 mol KOH = 0.817 mol K₃PO₄

Notice how when I set up this conversion calculation, the moles of KOH will cancel out to leave us with moles of K₃PO₄ as our final unit of measurement. Please reach out with a comment if you have any additional questions!