CHEM 14BL Study Guide - Final Guide: Analyte, Hydrolysis, Federal Food, Drug, And Cosmetic Act

• School: UCLA
• Department: Chemistry and Biochemistry
• Course: CHEM 14BL
• Professor: Henary Maher

Document Summary

Titrations/buffer chemistry: suppose that 15. 0 ml of 0. 15 m nh3 (aq) is titrated with 0. 10 m hcl (aq). Kb = 1. 8x10-5 x2/ (0. 15) => x= [(0. 15)(1. 8x10-5)] = . 0016431677 m = [oh-] % dissociation = [oh-]/[nh3] = (. 001643 m/ . 15m)*100% = 1. 1 % This is a buffer (weak base and its conjugate acid), Using the henderson hasselbalch equation will also provide the same answer: *let a- correspond to the base and ha correspond to the acid. ph = -log(5. 6x10-10) + log (. 025 m/ . 050 m) = 8. 95. The alternative to the henderson-hasselbalch equation is (this is just if your curious, don"t need to know this): *where bh+ denotes the conjugate acid of the corresponding weak base b* poh = -log(1. 8x10-5) + log ((. 050 m)/(. 025m)) = 5. 04 ph = 14 poh = 14. 00 5. 04 = 8. 95. If you don"t use henderson hasselbalch equation, take into account the hydrolysis of the conjugate acid,