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- Assume that an aqueous solution of OH-, represented as a blue sphere, is allowed to mix with a solution of an acid HnA, represented as a red sphere. Three possible outcomes are depicted by boxes (1)–(3), where the green spheres represent An-, the anion of the acid: Which outcome corresponds to each of the following reactions? (a) (b) (c)
Problem 41
- The concentration of an aqueous solution of NaOCl (sodium hypochlorite; the active ingredient in household bleach) can be determined by a redox titration with iodide ion in acidic solution:
Problem 42
Assume that the blue spheres in the buret represent I-ions, the red spheres in the flask represent OCl-ions, the con-centration of the I-ions in the buret is 0.120 M, and the volumes in the buret and the flask are identical. What is the concentration of NaOCl in the flask? What percentage of the I-solution in the buret must be added to the flask to react with all the OCl-ions?
Problem 42a
Classify each of the following unbalanced half-reactions as either an oxidation or a reduction. (a) HClO(aq) → Cl2(g)
Problem 42d
Classify each of the following unbalanced half-reactions as either an oxidation or a reduction. (d) SbCl4-(aq) → SbCl6-(aq)
Problem 43
Assume that the electrical conductivity of a solution depends on the total concentration of dissolved ions and that you measure the conductivity of three different solutions while carrying out titration procedures: (a) Begin with 1.00 L of 0.100 M KCl, and titrate by adding 0.100 M AgNO3. (b) Begin with 1.00 L of 0.100 M HF, and titrate by adding 0.100 M KOH. (c) Begin with 1.00 L of 0.100 M BaCl2, and titrate by adding 0.100 M Na2SO4. Which of the following graphs corresponds to which titration?
Problem 44
Based on the positions in the periodic table, which of the following reactions would you expect to occur? (a) Red+ + Green → Red + Green+ (b) Blue + Green+ → Blue+ + Green (c) Red + Blue+ → Red+ + Blue
Problem 45
The following two redox reactions occur between aqueous cations and solid metals. Will a solution of green cations react with solid blue metal? Explain.
(a)
(b)
Problem 46a
How many moles of solute are present in each of the following solutions? (a) 35.0 mL of 1.200 M HNO3
Problem 46b
How many moles of solute are present in each of the following solutions? (b) 175 mL of 0.67 M glucose (C6H12O6)
Problem 47a
How many grams of solute would you use to prepare each of the following solutions? (a) 250.0 mL of 0.600 M ethyl alcohol (C2H6O)
Problem 47b
How many grams of solute would you use to prepare each of the following solutions? (b) 167 mL of 0.200 M boric acid (H3BO3)
Problem 48a
How many milliliters of a 0.45 M BaCl2 solution contain 15.0 g of BaCl2?
- How many milliliters of a 0.350 M KOH solution contain 0.0171 mol of KOH?
Problem 49
- The sterile saline solution used to rinse contact lenses can be made by dissolving 400 mg of NaCl in sterile water and diluting to 100 mL. What is the molarity of the solution?
Problem 50
Problem 50a
Write balanced net ionic equations for the following reactions in acidic solution. (a) Zn(s) + VO2+(aq) → Zn2+(aq) + V3+(aq)
- The concentration of glucose (C6H12O6) in normal blood is approximately 90 mg per 100 mL. What is the molarity of the glucose?
Problem 51
- Copper reacts with dilute nitric acid according to the following equation: If a copper penny weighing 3.045 g is dissolved in a small amount of nitric acid and the resultant solution is diluted to 50.0 mL with water, what is the molarity of the Cu(NO3)2?
Problem 52
Problem 53a
The estimated concentration of gold in the oceans is 1.0 * 10^-11 g/mL. (a) Express the concentration in mol/L.
Problem 54a
How many grams of solute would you use to prepare the following solutions? (a) 500.0 mL of 1.25 M NaOH
Problem 54b
How many grams of solute would you use to prepare the following solutions? (b) 1.50 L of 0.250 M glucose (C6H12O6)
- How would you prepare 500 mL of a 0.330 M solution of CaCl2 from solid CaCl2? Specify the glassware that should be used.
Problem 55
- How would you prepare 250 mL of a 0.100 M solution of fluoride ions from solid CaF2? Specify the glassware that should be used.
Problem 56
- Pennies minted after 1982 are mostly zinc (97.5%) with a copper cover. If a post-1982 penny is dissolved in a small amount of nitric acid, the copper coating reacts as in Problem 4.52, and the exposed zinc reacts according to the following equation: For a penny that weighs 2.482 g, what is the molarity of the Zn(NO3)2 if the resultant solution is diluted to 250.0 mL with water?
Problem 57
- A bottle of 12.0 M hydrochloric acid has only 35.7 mL left in it. What will the HCl concentration be if the solution is diluted to 250.0 mL?
Problem 58
- What is the volume of the solution that would result by diluting 70.00 mL of 0.0913 M NaOH to a concentration of 0.0150 M?
Problem 59
- How would you prepare 250 mL of a 0.100 M solution of chloride ions from a 3.00 M stock solution of CaCl2? Spec-ify the glassware that should be used.
Problem 60
- How would you prepare each of the following solutions? (a) A 0.150 M solution of glucose in water
Problem 60
- How would you prepare 250 mL of 0.150 M solution of CaCl2 from a 3.00 M stock solution? Specify the glassware that should be used.
Problem 61
- The following aqueous solutions were tested with a light bulb conductivity apparatus, as shown in Figure 4.3. What result—dark, dim, or bright—do you expect from each? (a) 0.10 M potassium chloride (b) 0.10 M methanol (c) 0.10 M acetic acid
Problem 62
- A galvanic cell is constructed from a Zn/Zn2+ half-cell (anode) and a Cl2/Cl- half-cell (cathode). (b) Write balanced equations for the electrode and overall cell reactions.
Problem 63