Question

In analytical chemistry, bases used for titrations must often be standardized; that is, their concentration must be precisely determined. Standardization of sodium hydroxide solutions can be accomplished by titrating potassium hydrogen phthalate (KHC8H4O4), also know as KHP, with the NaOH solution to be standardized.

The titration of 0.5727 g of KHP required 24.70 mL of an NaOH solution to reach the equivalence point. What is the concentration of the NaOH solution?

Answer 1

The titration of 0.5727 g of KHP required 24.70 mL of an NaOH solution to reach the equivalence point. What is the concentration of the NaOH solution?

number of moles of NaOH in thevolume given is equal to the number of moles of KHP. Divide moles of NaOH by volume (in liters) to get molarity molar mass of KHP

(KHC8H4O4) = [39.1 g + 5(1.008 g) + 8(12.01 g) +4(16.00 g)] = 204.2 g/mol

Solution moles of KHP =0.5727 /204.2 g/mol=0.00280 mol

Because moles of KHP = moles of NaOH, then moles of NaOH = 0.00280 mol

concentration of the NaOH solution =0.00280 mol /0.02470 L=0.11336M------ANSWER