Study Guide for CHEM 102 Test 4 Fall 2007

    1. Define the terms below:

      1. Bronsted-Lowry acid
      2. Bronsted-Lowry base
      3. Lewis acid
      4. Lewis base
      5. amphoteric
      6. pH
      7. pOH

    2. What is the pH of an aqueous solution that is 0.00897 M in hydrogen ion (H+(aq)) concentration? What is the pOH?

    3. What is the hydroxide ion concentration ( [OH-] ) of an aqueous solution that has a pH of 13.31? What is the hydrogen ion concentration ( [H+] )?

    4. Put the acids in each part below in order from strongest to weakest.)

      1. HClO, HClO4, HClO2, HClO3

      2. H3SbO4, H3PO4, H3BiO4, H3AsO4

    5. Find the pOH and pH of the solutions below:

      1. a solution where [H+] = 3.86 x 10-16

      2. a solution where [OH-] = 6.22 x 10-6

      3. a solution where [OH-] = [H+]

      4. a solution where the hydroxide ion concentration is equal to double the hydrogen ion concentration

      5. a solution where [OH-] = 1.06 x 10-12

    6. What is the pH of a solution that is 4.850 M in NaNO2 and 0.750 M in HNO2? The KA for HNO2 is 4.5 x 10-4.
      HNO2(aq) <----------> H+(aq) + NO2-(aq)

    7. What is the pH of a buffer solution that is 2.00 M in sodium benzoate (NaOOCC6H5) and 0.100 M in benzoic acid (HOOCC65)? The KA of benzoic acid is 6.3 x 10-5.

      HOOCC6H5(aq)<---------> H+(aq) + -OOCC6H(aq)

    8. Using the buffer solution in the problem above, what is the pH if 15.00 mL of 2.50 M HCl(aq) is added to 75.00 mL of the buffer solution? What would be the pH if 25.00 mL of 1.45 M NaOH was added to 85.00 mL of the buffer solution in problem the problem above?

    9. What is the percent ionization for the following solutions of acids?

      1. 2.50 M HC2H3O2, KA = 1.8 x 10-5

      2. 0.00500 M HCOOH, KA = 1.7 x 10-4

      3. 0.1500 M C6H5OH, KA = 1.3 x 10-10

      4. 0.000515 M HF(aq), KA = 7.1 x 10-4

      5. 0.00180 M HC9H7O4, KA = 3.0 x 10-4

    10. What is the sulfate concentration in a 14.00 M H2SO4(aq) solution? Ka1 = extremely large, ~100 % dissociation, KA2 = 1.3 x 10-2.

    11. What is the arsenate concentration (AsO43-) in 3.00 M arsenic acid (H3AsO4)? KA1 = 6.0 x 10-3, KA2 = 1.05 x 10-7, KA3 = 3.0 x 10-12

    12. What is the pH of a solution that is

      1. 6.50 M in NaC2H3O2, HC2H3O2 KA = 1.8 x 10-5

      2. 2.60 M in NaCN, HCN KA = 2.1 x 10-9

      3. 4.50 M in NH4Cl, NH3 KB = 1.8 x 10-5

      4. 2.34 M in NaIO3, HIO3 KA = 1.58 x 10-1

      5. 2.95 M in NaN3, HN3 KA = 1.9 x 10-5

    13. What is the pH of a buffer that is 3.93 M in NaCN and 0.951 M in HCN? If 10.00 mL of 0.1500 M HCl is added to 100.00 mL of this buffer what is the pH? If 15.00 mL of 0.6000 M NaOH is added to 95.00 mL of this buffer what is the pH?

      HCN(aq)<--------> H+(aq) + CN-(aq) KA = 2.1 x 10-9

    14. Design buffers with the at pH = 5.00 with the following

      1. a system 1.00 M in HC2H3O2, KA = 1.8 x 10-5

      2. a system 0.750 M in NaCN, HCN KA = 2.1 x 10-9

      3. a system 1.00 M in NH3, KB = 1.8 x 10-5

      4. a system 1.00 M in NH4Cl, NH3 KB = 1.8 x 10-5

      5. a system 1.00 M in NaC2H3O2, HC2H3O2 KA = 1.8 x 10-5

    15. What are the equilibrium concentrations of the reactants and products below if a solution was made that was initially 1.00 M in Cl3CCOOH(aq), 0.500 M in H+(aq) and 0.325 M in Cl3CCOO-(aq)? The KA = 1.29 x 10-1

    16. What is the molar solubility of PbSO4 if the Ksp for PbSO4 is 1.3 x 10-8?

      PbSO4(s) <----------> Pb2+(aq) + SO42-(aq)

    17. What is Ksp of CaF2 if the molar solubility of CaF2 is 2.136 x 10-4 M?

    18. If the molar solubility of Fe(OH)2 is 5.85 x 10-6, what is Ksp for Fe(OH)2?

      Fe(OH)2(s) <----------> Fe2+(aq) + 2 OH-(aq)
    19. If the Ksp for Mn(OH)2 is 2.00 x 10-13, what is the molar solubility of Mn(OH)2?

      Mn(OH)2(s) <-----------> Mn2+(aq) + 2 OH-(aq)

    20. What is the molar solubility of AgCl in 1.00 M NaCN?

      KspAgCl = 1.6 x 10-10, KfAg(CN)2 = 1.0 x 1021.

    21. What is the molar solubility of Zn(OH)2? What is its molar solubility in a solution buffered at pH 14? At pH 5? The solubility product for Zn(OH)2 is 2.1 x 10-14.

    22. Define:

      1. Ksp
      2. Kf
      3. buffer
      4. buffer capacity
      5. Kd
      6. common ion effect
      7. pKA
      8. pKB
      9. titration
      10. molar solubility
      11. complex ion

    23. What is the solubility of AgCl in 5.00 M NH3?

      AgCl(s) <---------> Ag+(aq) + Cl-(aq) ; Ksp = 1.8 x 10-10

      Ag+(aq) + 2 NH3(aq) <---------> Ag(NH3)2+(aq) ; Kf = 1.7 x 107

    24. Explain how the pKA of a weak acid may be determined via a pH titration.

    25. Are the solutions below acidic or basic?

      1. 3.00 M Na+F-

      2. 3.00 M Na+C2H3O2-

      3. 3.00 M NH4+Cl-

      4. 3.00 M CH3CH2NH3+Cl-

    26. What is the molar solubility of AgCl in 1.00 M NaCN?

      KspAgCl = 1.6 x 10-10, KfAg(CN)2 = 1.0 x 1021.

    27. What is the molar solubility of Zn(OH)2? What is its molar solubility in a solution buffered at pH 14? At pH 5? The solubility product for Zn(OH)2 is 2.1 x 10-14.