CHE 110L Lecture Notes - Lecture 5: Molar Mass, Phenolphthalein, Molar Concentration

• School: Quinnipiac University
• Department: Chemistry
• Course: CHE 110L
• Professor: Stephen Madison

Document Summary

Determining the molar mass of an unknown acid by titration. The purpose of this experiment was to standardize a sodium hydroxide solution by titration with potassium hydrogen phthalate, khp, using phenolphthalein as an indicator. The standardized sodium hydroxide solution was then titrated with an unknown acid to determine its molar mass. The procedure for this lab can be found on pages 54-57 in general chemistry che110l. Carbon copies of data tables have been attached to the back of this lab report. 0. 599 g khp x 1 mol khp = 0. 00293 mol khp = 0. 00293 mol naoh. 0. 601 g khp x 1 mol khp = 0. 00294 mol khp = 0. 00294 mol naoh. 0. 621 g khp x 1 mol khp = 0. 00304 mol khp = 0. 00304 mol naoh. Mnaoh= (0. 00304 mol)/(0. 0292 l) = 0. 104 m: average naoh molarity. 0. 115 m + 0. 104 m + 0. 104 m = 0. 108 m. 0. 007 + 0. 004 + 0. 004 = 0. 005 m.