when 200. milliliters of an HNO3 solution is exactly neutralized by 250 milliliters of a 0.50 M solution of KOH, what is the concentration of HNO3

Molarity HNO₃ Soln = 0.625M

Explanation:

Molarity of Acid Soln X Volume Acid Soln = Molarity of Base Soln x Volume of Base Soln

Molarity HNO₃ Soln x 200-ml HNO₃ Soln = 0.50M KOH Soln x 250-ml KOH Soln

Molarity HNO₃ Soln = (0.50M) (250ml) / (200ml) = 0.625M