Assume that an aqueous solution of a cation, represented as a red sphere, is allowed to mix with a solution of an anion, represented as a yellow sphere. Three possible outcomes are represented by boxes (1)–(3): 4.24 Which outcome corresponds to each of the following reactions? (a) 2 Na+(aq) + CO32(aq) (b) Ba2+(aq) + CrO42-(aq) (c) 2 Ag+(aq) + SO32(aq)

Assume that an aqueous solution of a cation, represented as a blue sphere, is allowed to mix with a solution of an anion, represented as a green sphere, and that the following result is obtained: 4.25 Which combinations of cation and anion, chosen from the following lists, are compatible with the observed results? Explain. Cations: Na+, Ca2+, Ag+, Ni2+ Anions: Cl, Ca32, CrO42, NO3

4.26 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 On, the anion of the acid: Which outcome corresponds to each of the following reactions? (a) HF + OH H2O + F (b) H2SO3 + 2 OH 2 H2O + SO32 (c) H3PO3 + 2 OH 3 H2O + PO43

4.27 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: Ocl(aq) + 2 I(aq) + 2 H+(aq) Cl–(aq) + I2(aq) + H2O(l) Assume that the blue spheres in the buret represent I ions, the red spheres in the flask represent Ocl ions, the concentration 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?

Assume that the 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 addition of 0.100 M AgNO3. (b) Begin with 1.00 L of 0.100 M HF, and titrate by addition of 0.100 M KOH. (c) Begin with 1.00 L of 0.100 M BaCl2 and titrate by addition of 0.100 M Na2SO4. Which of the following graphs corresponds to which titration? 4.28

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 4.29