Student A weighs 0.747g of KHP on a laboratory balance. The KHP was titrated wit
ID: 1035204 • Letter: S
Question
Student A weighs 0.747g 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 0.113M. Student B diluted 6M HCl from the reagent shelf using a volumetric flask to obtain 0.6M HCl. This solution was titrated with the same unknown NaOH solution and found to be 0.104 M. Why does student B have a more accurate concentration for the unknown NaOH? Student A weighs 0.747g 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 0.113M. Student B diluted 6M HCl from the reagent shelf using a volumetric flask to obtain 0.6M HCl. This solution was titrated with the same unknown NaOH solution and found to be 0.104 M. Why does student B have a more accurate concentration for the unknown NaOH?Explanation / Answer
Titration with NaOH will give a more accurate result with HCl because HCl is a strong acid and is therefore completely dissociated whereas KHP being a weak acid does not dissociate completely therefore the reaching of the end point will also depend on the degree of dissociation of the weak acid which makes the result less accurate.