Chapter 16, Problem 60AP

Calcium carbonate, CaCO3, can be obtained in a very pure state. Standard solutions of calcium ion are usually prepared by dissolving calcium carbonate in acid. What mass of CaCO3 should be taken to prepare 500. mL of 0.0200 M calcium ion solution?

Lead poisoning has been a hazard for centuries. Some scholars believe that the decline of the Roman Empire can be traced, in part, to high levels of lead in water from containers and pipes, and from wine that was stored in leadglazed containers. If we presume that the typical Roman water supply was saturated with lead carbonate, PbCO3 (Ksp = 7.4 1014), how much lead will a Roman ingest in a year if he or she drinks 1 L/day from the container?

A mountain lake that is 4.0 km × 6.0 km with an average depth of 75 m has an H+(aq) concentration of 1.3 × 10−6 M. Calculate the mass of calcium carbonate that would have to be added to the lake to change the H+(aq) concentration to 6.3 × 10−8 M. Assume that all the carbonate is converted to carbon dioxide, which bubbles out of the solution.

How would you prepare from the solid and pure water (a) 0.400 L of 0.155 M Sr(OH)2? (b) 1.75 L of 0.333 M (NH4)2CO3?

You are given four different aqueous solutions and told that they each contain NaOH, Na2CO3, NaHCO3, or a mixture of these solutes. You do some experiments and gather these data about the samples. Sample A: Phenolphthalein is colorless in the solution. Sample B: The sample was titrated with HCl until the pink color of phenolphthalein disappeared, then methyl orange was added. The solution became pink. Methyl orange changes color from pH 3.01 (red) to pH 4.4 (orange). Sample C: Equal volumes of the sample were titrated with standardized acid. Using phenolphthalein as an indicator required 15.26 mL of standardized acid to change the phenolphthalein color. The other sample required 17.90 mL for a color change using methyl orange as the indicator. Sample D: Two equal volumes of the sample were titrated with standardized HCl. Using phenolphthalein as the indicator, it took 15.00 mL of acid to reach the equivalence point; using methyl orange as the indicator required 30.00 mL HCl to achieve neutralization. Identify the solute in each of the solutions.

efine the term strong electrolyte. What types of substances tend to be strong electrolytes? What does a solution of a strong electrolyte contain? Give a way to determine if a substance is a strong electrolyte.

What mass of solid aluminum hydroxide can be produced when 50.0 mL of 0.200 M Al(NO3)3 is added to 200.0 mL of 0.100 M KOH?

Solubility and Solubility Product You put 0.10-mol samples of KNO3, (NH4)2S, K2S, MnS, AgCl, and BaSO4 into separate flasks and add 1.0 L of water to each one. Then you stir the solutions for 5 minutes at room temperature. Assume that you have 1.0 L of solution in each case. a Are there any beakers where you would observe solid still present? How do you know? b Can you calculate the potassium ion concentration, K+, for the solutions of KNO3 and K2S? If so, do the calculations, and then compare these K+ concentrations. c For the solutions of (NH4)2S, K2S, and MnS, how do the concentrations of sulfide ion, S2, compare? (You dont need to calculate an answer at this point; just provide a rough comparison.) Be sure to justify your answer. d Are there any cases where you need more information to calculate the sulfide-ion concentration for the solutions of (NH4)2S, K2S, and MnS from part c? If so, what additional information do you need? e Consider all of the solutions listed at the beginning of this problem. For which ones do you need more information than is given in the question to determine the concentrations of the ions present? Where can you find this information? f How is the solubility of an ionic compound related to the concentrations of the ions of the dissolved compound in solution?

Follow the directions of Question 21 for the following bases: (a) toluidine, C7H9N (b) strontium hydroxide (c) indol, C8H6NH (d) aqueous ammonia