Question

A volume of 10.0 mL of a 0.130 M HNO3 solution is titrated with 0.580 M KOH. Calculate the volume of KOH required to reach the equivalence point.

Express your answer to three significant figures and include the appropriate units.

Answer 1

Ans. # Step 1: Moles of HNO3 taken = Molarity x Vol. of soln. in liters

                                                = 0.130 M x 0.010 L = 0.0013 mol

#Step 2: Balanced reaction: HNO₃(aq) + KOH(aq) ----> KNO₃(aq) + H₂O(l)

Following stoichiometry of balanced reaction, 1 mol HNO₃ is neutralized by 1 mol KOH.

So, the moles of KOH consumed to reach the equivalence point must be equal to the moles of HNO₃ taken.

So,

            Required moles of KOH = Moles of HNO₃ taken = 0.0013 mol

# Step 3:

            Required vol. of KOH soln. = Required moles / Molarity

                                                = 0.0013 mol / 0.580 M

                                                = 0.0013 mol / (0.580 mol / L)

                                                = 0.002241 L = 2.24 mL