12_new - Homework #9 holcombe (51160) 1 This print-out...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 This print-out should have 15 questions. 5 . 2 × 10 −19 Multiple-choice questions may continue on 4. the next column or page find all choices 1 . 69 × 10 −14 before answering. 5. 001 10.0 points A student titrated a sample containing 102 mL of 0 . 3 M NaOH with 0 . 67 M HCl. What is the pH of the solution after 20 mL of the hydrochloric acid has been added? 1. 7 2. 14 . 16 3. 0 . 84 4. 13 . 16 correct 5. − 0 . 16 Explanation: V NaOH = 102 mL [NaOH] = 0 . 3 M V HCl = 20 mL [HCl] = 0 . 67 M Initially n NaOH : (102 mL)(0 . 3 M) = 30 . 6 mmol n HCl : (20 mL)(0 . 67 M) = 13 . 4 mmol NaOH + HCl NaCl ini 30 . 6 mmol 13 . 4 mmol +H 2 O 13 . 4 mmol 13 . 4 mmol fin 17 . 2 mmol 0 mmol V new = 102 mL + 20 mL = 122 mL [NaOH] = 17 . 2 mmol = 0 . 141 M = [OH ] 122 mL pOH = log[OH ] = log(0 . 141) = 0 . 84 pH = 14 pOH = 14 0 . 84 = 13 . 16 002 10.0 points What is K sp for AgI, if its molar solubility is 9 . 1 × 10 −9 mol / L? 1. 6 . 9 × 10 −9 2. 1 . 4 × 10 −21 3. 0.0053 6. 7 . 744 × 10 −13 7. 8 . 281 × 10 −17 correct Explanation: S = 9 . 1 × 10 −9 mol / L The solubility equilibrium is AgI(s) Ag + (aq) + I (aq) [Ag + ] = [I ] = S = 9 . 1 × 10 −9 mol / L K sp = [Ag + ][I ] = 9 . 1 × 10 −9 2 = 8 . 281 × 10 −17 003 10.0 points What is K sp for Ca(OH) 2 , if its molar solu-bility is 0 . 011 mol / L? 1. 5 . 2 × 10 −25 2. 1 . 4 × 10 −21 3. 5 . 3 × 10 −6 correct 4. 1 . 7 × 10 −14 5. 6 . 9 × 10 −11 6. 4 . 7 × 10 −30 7. 8 . 3 × 10 −8 Explanation: S = 0 . 011 mol / L The solubility equilibrium is
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/04/2012 for the course CH 302 taught by Professor Holcombe during the Spring '07 term at University of Texas at Austin.

Page1 / 5

12_new - Homework #9 holcombe (51160) 1 This print-out...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online