Question

In an acid-base titration, 22.13 mL of a NaOH solution are needed to neutralize 24.65 mL of the potassium hydrogen phthalate solution. Determine the molarity of the NaOH solution. Start with a balanced equation.

Answer 1

KHT + NaOH --------------> KNaT + H2O

according to balanced reaction

kHT and NaOH are 1 : 1 ratio.

so if we know either kHT or NaOH we can find the concentration of other.

if we know potassium hydrogen phthalate concentration of NaOH

from question 1 calculate the molarity of the solution

Molarity = (W/MW) (1000 / volume of solution)

Molarity = (0.8954 / 204.23) (1000/100)

Molarity = 0.044 M

[KHT] = 0.04384 M

millimoles of KHT = 24.65 x 0.04384 = 1.081

1.081 millimoles NaOH must be added

1.081 = 22.13 X M

M = 0.0488

Molarity of NaOH = 0.04884 M