Question

Consider the reaction: 3HNO3(aq) + K3PO4(aq)  H3PO4 + 3KNO3(aq) What is the concentration of an HNO3 solution if 25.0 mL reacts with 38.5 mL of 0.145 M K3PO4?

Answer 1

Moles of $K_3PO_4=0.145×0.0385=0.0056moles$

Moles of $HNO_3=0.0056×3=0.0168moles$

Molarity $=\frac{0.0168}{0.025}=0.672M$