318.405 g
We are given;
We are required to determine the mass of K₃PO₄ to be measured.
Molarity = Moles ÷ Volume
Rearranging the formula;
Number of moles = Molarity × Volume
Therefore;
Moles of K₃PO₄ = 2.00 M × 0.75 L
= 1.5 moles
Mass = Number of moles × Molar mass
Molar mass of K₃PO₄ = 212.27 g/mol
Therefore;
Mass of K₃PO₄ = 1.5 moles × 212.27 g/mol
= 318.405 g
Therefore, the mass of K₃PO₄ that should be weighed is 318.405 g