75.0 mL of 15.0 M HNO3 was diluted to exactly 500 mL by adding water. What is the final molarity of the diluted HNO3 solution?

The final molarity is 2,25M.

Explanation:

A dilution consists of the decrease of concentration of a substance in a solution (the higher the volume of the solvent, the lower the concentration).

We use the formula for dilutions:

C1 x V1 = C2 x V2

15,0 M x 75 ml = C2 x 500 ml

C2 = (15,0M x 75 ml) / 500ml

C2=2,25 M