Chapter 13 Solutions Problems!

Do your work on a separate piece of paper. Be sure to show all work clearly and mark answers clearly in a box or circle.

Mass % Problems

  1. Conisder a solution of glucose in water that is 5.25% by mass glucose. Calculate the indicated quantities
  2. The mass of glucose in 225 g of the solution
  3. The number of grams of glucose needed to prepare 225 g of the solution
  4. The amount of solution needed to obtain 25.0 gram of glucose
  5. The mass of water contained in 225 g of the solution.

Molarity:

  1. If 45.3 g sample of potassium nitrate is dissolve din enough water to make 225 mL of solution, what will be the molarity?
  1. Suppose 1.01 g of FeCL3 is placed in a 10.0 mL volumetric flask, water is added, the mixture is shaken to dissolve the solid, and then water is added to the calibration mark of the flaks. Calculate the molarity of each ion present in the solution.

Dilution:

  1. A chemistry student needs 125 mL of 0.150 M NaOH solution for her experiment, but the only solution available in the laboratory is 3.02 M. Describe how the students could prepare the solution she needs.
  1. If 75 mL of 0.211 M NaOH is diluted to a final volume of 1224mL, what is the concentration of NaOH in the diluted solution?

Stoichiometry of Solution Reactions:

  1. Calculate the mass of solid NaCl that must be added to 1.50 L of a 0.100 M AgNO3 solution to precipitate all of the Ag+ ions in the form of AgCl. Calculate the mass of AgCl formed.
  1. When Ba(NO3)2 and K2CrO4 react in aqueous solution, the yellow solid BaCrO4 is formed. Calculate the mass of BaCrO4 that forms when 3.50 x10–3 mol of solid Ba(NO3)2 is dissolved in 265 mL of 0.0100 M K2CrO4 Solution.
  1. What volume (in mL) of 0.25 M Na2So4 solution is needed to precipitate all the barium, as BaSO4(s), form 12.5 mL of 0.15 M Ba(NO3)2

Ba(NO3)2 (aq) + Na2SO4 (aq)  BaSO4(s) + 2NaNO3 (aq)

  1. One way to determine the amount of chloride ion in a water sample is to titrate the sample with standard silver nitrate solution to produce solid silver chloride. If a 25.0 mL water sample requires 27.2 mL of 0.104 M silver nitrate in such a titration, what is the concentration of chloride ion in the sample?

Ag+ (aq) + Cl-(aq)  AgCl (s)

  1. Many metal ions are precipitated form solution by the sulfide ion. As an example, consider treating a solution of copper(II) sulfate with sodium sulfide solution. What volume of 0.105 M sodium sulfide solution would be required to precipitate all of the copper (II) ion form 27.5 mL of 0.121 M copper(II) sulfate solution?

CuSO4(aq) + Na2S(aq)  CuS(s) + Na2SO4 (aq)

  1. When aqueous solutions of lead(II) ion are treated with potassium chromate solution, a bright yellow precipiatate of lead(II) chromate, PbCrO4, forms. How many grams of lead chromate form when a 1.00g sample of Pb(NO3)2 is added to 25 mL of 1.00 M K2CrO4 solution?

Extra Credit:

  1. Aluminum ion may be precipitated from aqueous solution by addition of hydroxide ion, forming Al(OH)3. A large excess of hydroxide ion must be added, however, because the precipitate of Al(OH)3 will redissolve to form a soluble aluminum/hydroxide complex. How many grams of solid NaOH should be added to 10.0 mL of 0.240 M AlCl3 to just precipitate all the aluminum?