Student A weight 0.747 g of KHP on a laboratory balance.

Question

Student A weight 0.747 g of KHP on a laboratory balance. The KHP was titrated with an unknown NaOH solution and the concentration of the NaOH was determined to be 0.113 M. Student B diluted 6 M HCl from the reagent shelf using volumetric flask to obtain 0.6 M HCl. This solution was titrated with the same unknown NaOH solution and found to be 0.140 M. Which student should have the accurate concentration for the unknown NaOH? Why

Answer 1

Student A would have the more accurate result. The reason is because KHP is a solid and can be weighed more accurately than HCl can be measured as a liquid. Also, KHP is considered to be a primary standard because of this and the fact that it is stable.