Question

Potassium acid phthalate, KHC₈H₄O₄, or KHP, is used in many laboratories, including general chemistry laboratories, to standardize solutions of base. KHP is one of only a few stable solid acids that can be dried by warming and weighed. A 0.3574 g sample of KHC₈H₄O₄ reacts with 34.79 mL of a NaOH solution in a titration. What is the molar concentration of the NaOH? Here is the equation given below.

KHC₈H₄O₄(aq) + NaOH(aq) → KNaC₈H₄O₄(aq) + H₂O(l)

Answer 1

Reaction is

KHC₈H₄O_4(aq) + NaOH_(aq) → KNaC₈H₄O_4(aq) + H₂O_(l)

moar mass of KHC₈H₄O₄ = 204.44 gm/mole that mean 1 mole of KHC₈H₄O₄ = 204.44gm then

0.3574 gm = 0.3574/204.44 = 0.001748 mole of KHC₈H₄O₄

According to reaction 1 mole of KHC₈H₄O₄ react with 1 mole of NaOH then 0.001748 mole KHC₈H₄O₄ react with 0.001748 mole of NaOH

thus mole of NaOH = 0.001748 mole

34.79 ml = 0.03479 L

Molarity = no. of mole of solute/ volume of solution in liter

Molarity of NaOH = 0.001748/0.03479 = 0.05M

Molarity of NaOH = 0.05M