1 methyl red 2 phenolphthalein correct 3 phenol red 4

This preview shows page 5 - 6 out of 6 pages.

1. methyl red 2. phenolphthalein correct 3. phenol red 4. methyl orange 5. alizarin Explanation: Phenolphthalein has a p K In range that overlaps the pH at the equivalence point. 015 10.0 points Which of the following indicators would be most suitable for the titration of 0.10 M lactic acid with 0.10 M KOH(aq)? For lactic acid, p K a = 3.08. 1. methyl orange (p K In = 3.4) 2. bromophenol blue (p K In = 3.9) 3. phenol red (p K In = 7.9) correct 4. alizarin yellow (p K In = 11.2) 5. thymol blue (p K In = 1.7) Explanation: 016 10.0 points What is the molar solubility of CaF 2 ? ( K sp = 3 . 9 × 10 - 11 .) 1. 2 . 1 × 10 - 4 correct 2. 3 . 9 × 10 - 11 3. 4 . 4 × 10 - 6 4. 6 . 2 × 10 - 6 5. 3 . 4 × 10 - 4 Explanation: CaF 2 Ca 2+ + 2 F - K sp = [Ca 2+ ] [F - ] 2 3 . 9 × 10 - 11 = ( x ) (2 x ) 2 = 4 x 3 x = 2 . 1 × 10 - 4 017 (part 1 of 2) 10.0 points Find the Q sp when 5 mL of 0 . 18 M K 2 CO 3 (aq) and 1 L of 0 . 019 M AgNO 3 (aq) are mixed together. The solubility product of Ag 2 CO 3 is 6 . 2 × 10 - 12 . Correct answer: 3 . 20075 × 10 - 7 . Explanation: V K 2 CO 3 = 5 mL = 0 . 005 L m K 2 CO 3 = 0 . 18 M V AGNO 3 = 1 L m AGNO 3 = 0 . 019 M V tot = 0 . 005 L + 1 L = 1 . 005 L [Ag + ] = (0 . 019 M) · 1 L 1 . 005 L = 0 . 0189055 M [CO 2 - 3 ] = (0 . 18 M) · 0 . 005 L 1 . 005 L = 0 . 000895522 M The reaction is Ag 2 CO 3 (s) 2 Ag + (aq) + CO 2 - 3 (aq) Q sp = [Ag + ] 2 [CO 2 - 3 ] = (0 . 0189055) 2 (0 . 000895522) = 3 . 20075 × 10 - 7 018 (part 2 of 2) 10.0 points Will a precipitate form? 1. Yes correct 2. No Explanation: K sp = 6 . 2 × 10 - 12 A precipitate will form because Q sp > K sp . 019 10.0 points Given the following reactions at equilibrium in an aqueous solution.
Image of page 5

Subscribe to view the full document.

estrada (gse77) – Homework 9 – Sutcliffe – (52410) 6 CaCO 3 (s) Ca 2+ + CO 2 - 3 CO 2 - 3 + H + HCO - 3 HCO - 3 + H + H 2 CO 3 H 2 CO 3 H 2 O + CO 2 (aq) CO 2 (aq) CO 2 (g) Ca 2+ + S - 2 CaS(s) Which of the following would not increase the molar solubility of CaCO 3 ? 1. Add K 2 CO 3 (a strong electrolyte) to the solution. correct 2. Pump away the CO 2 (g) above the solu- tion. 3. Buffer the solution at pH = 4 rather than adjust the initial pH by adding HCl. 4. Lower the solution pH. 5. Add H 2 S to the solution. Explanation: 020 10.0 points Rank the following compounds from most soluble to least soluble. Assume that all bonds except the OH are ionic. (You can estimate this ranking without using a calculator.) Compound K sp Bi 2 S 3 1 . 0 × 10 - 97 Fe(OH) 2 1 . 6 × 10 - 14 PbI 2 2 . 6 × 10 - 13 HgS 1 . 6 × 10 - 52 1. PbI 2 > Fe(OH) 2 > HgS > Bi 2 S
Image of page 6
You've reached the end of this preview.
  • Fall '07
  • Holcombe
  • pH, ml, Equivalence point, ESTRADA

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern