Schedule Today (3/4): Continue Chapter 8 Should have read through Section 8.7 (at least) Wednesday (3/6): Continue Chapter 8 Should have read through Section 8.8 (at least) Friday (3/8): Continue Chapter 8 Should have read all of Chapter 8 Monday (3/11): Finish Chapter 8

Titrations with 0.100M NaOH 25.0 mL of 0.100M HCl 25.0 mL of 0.100M HC2H3O2 (Ka=1.8 x 10–5; pKa=4.74)

Clicker Question What are the major species? Determine the pH of a 1.00M aqueous solution of NaHCO3. Ka1 for H2CO3 = 4.3 x 10–7 Ka2 for H2CO3 = 4.8 x 10–11 What are the major species? What are the reactions in solution? Which reaction dominates?

Clicker Question a) 6.37 b) 7.52 c) 8.09 d) 8.34 e) 10.32 Determine the pH of a 2.00M aqueous solution of NaHCO3. Ka1 for H2CO3 = 4.3 x 10–7 Ka2 for H2CO3 = 4.8 x 10–11 a) 6.37 b) 7.52 c) 8.09 d) 8.34 e) 10.32

Polyprotic Acids: H2CO3 Ka1 = 4.3 x 10–7 Ka2 = 4.8 x 10–11 pKa1 = 6.37 pKa2 = 10.32

Diprotic Acid Titration pH Curve Essentially two pH curves!

Polyprotic Acids: H3PO4 pKa1 = 2.12 pKa2 = 7.21 pKa3 = 12.32 Ka1 = 7.5 x 10–3 Ka2 = 6.2 x 10–8 Ka3 = 4.8 x 10–13

Trprotic Acid Titration pH Curve

Polyprotic acid titration: H3PO4