PRE-TEST  3                   


You may take values of Ka, Ksp, and
Kf from tables in the textbook.  

Points

1.    Determine the pH of the following solutions:

(7)   (a)  2.63 g of Ca(OH)2 is dissolved in enough water to make
           1.00 L of solution.
















(7)   (b)  0.250 L of 0.200 M HCl solution is added to the Ca(OH)2
           solution in part 1(a).  









(7)   (c)  How many L of 0.200 M HCl solution would have to be added
           to the Ca(OH)2 solution in part 1(a) to produce a pH of
           7.0?
















2.    Determine the pH of the following solutions:

(8)   (a)  2.63 grams of sodium acetate is added to enough water to
           make 1.00 L of solution.
















(8)   (b)  0.100 L of 0.200 M HCl solution is added to the solution
           of sodium acetate in part 2(a) above.











(8)   (c)  0.100 L of 0.200 M acetic acid solution is added to the
           solution of sodium acetate in part (a) above.



















(5)3. What is the [HCO3-]/[H2CO3] ratio in blood at pH 7.40?










(8)4. You have made a buffer of formic acid at pH 3.00 in which the
      total formic acid + formate concentration ([HCOOH] + [HCOO-]
      is equal to 0.0500 M.  What are the concentrations of [HCOOH]
      and [HCOO-]?













5.    How many grams of barium sulfate will dissolve in:

(5)   (a)  1.00 L of water?









(5)   (b)  1.00 L of 0.050 M Na2SO4 salt solution?










(6)6. What is the pH of a saturated solution of Mn(OH)2?
















(6)7. Calculate the equilibrium constant for the following reaction:

      CuCO3(s)  +  4 NH3(aq)  ---->   Cu(NH3)42+   +   CO32-









(6)8. For the reaction: CH4(g) + 2 O2(g) ----> CO2(g) + 2 H2O(g)

      The initial rate of change of [CH4] is -0.15 Ms-1.  Give the
      initial rate of change of:

      [O2]  ________  [CO2] ________  [H2O] ________


(6)9. The rate law for the following reaction is first order in H2
      and second order in NO, with a rate constant k at 1000 K of
      6.0 X 104 M-2s-1.  

      2 NO(g)  +  2 H2(g)  ---->   N2(g)   +    2 H2O(g)

      What is the rate of the reaction under the following
      conditions?

      [H2]            [NO]            rate

      0.055 M       0.012 M    _______________________

      0.110 M       0.012 M    _______________________

      0.055 M       0.024 M    _______________________


(8)10.The decomposition of hydrogen peroxide to water and oxygen
      follows a first order rate law in H2O2 with a half-life of
      18 min.

           2 H2O2(l)  ----->   H2O(l)  +   O2(g)

      (a)  What is the rate constant k for the reaction?







      (b)  Starting with a solution that is 0.500 M in hydrogen
           peroxide, what will be the hydrogen peroxide
           concentration after 60 min?