100mL of a solution (an unknown monoprotic acid) is titrated with 0.250 M KOH.The titration requires 32.70 mL of the KOH to reach the equivalence.What's the molar concentration of the acid?

Question

Suppose

100.0 mL of an aqueous solution containing an unknown

monoprotic acid

(called HA)

is titrated with 0.

250

M KOH. The titration requires 32.70

mL of the potassium

hydroxide

to reach the equivalence point. What is the molar

concentration of

the unknown acid

solution?

Answer 1

Let the monoprotic acid be HA.

HA + KOH ==> KA + H2O

moles KOH used = 0.0327 L x 0.25 mol/L = 0.008175 moles

moles HA present = 0.008175 (1:1 mole ratio)

Concentration of HA = 0.008175 mol/0.100 L = 0.0188 M