Calculate the mass (in grams) of sodium sulfide that is needed to make 350 mL of a 0.50 mol/L solution. 2.In a lab 42.6 mL of sulfuric acid precipitates exactly 3.260 g of barium sulfate from a solution of barium hydroxide. What is the molar concentration of the sulfuric acid?

Consider a 1.50-g mixture of magnesium nitrate and magnesium chloride. After dissolving this mixture in water, 0.500 M silver nitrate is added dropwise until precipitate formation is complete. The mass of the white precipitate formed is 0.641 g. a. Calculate the mass percent of magnesium chloride in the mixture. b. Determine the minimum volume of silver nitrate that must have been added to ensure complete formation of the precipitate.

Separate samples of a solution of an unknown soluble ionic compound are treated with KCl, Na2SO4, and NaOH. A precipitate forms only when Na2SO4 is added. Which cations could be present in the unknown soluble ionic compound?

3.63 How many moles of solute are present in each of these solutions? (a) 48.0 mL of 3.4 M H2SO4. (b) 1.43 mL of 5.8 M KNO3. (c) 321 L of 0.034M NH3 (d) 1.9 × 10-3 L of 1.4 × 10-5 M NaF

The cations Ba2+ and Sr2+ can be precipitated as very insoluble sulfates. (a) If you add sodium sulfate to a solution containing these metal cations, each with a concentration of 0.10 M, which is precipitated first, BaSO4 or SrSO4? (b) What will be the concentration of the first ion that precipitates (Ba2+ or Sr2+) when the second, more soluble salt begins to precipitate?

When solutions of BaCl2 and Na2SO4 are mixed, the mixture becomes cloudy. After a few days, a white solid is observed on the bottom of the beaker with a clear liquid above it. (a) Write a balanced equation for the reaction that occurs. (b) Why is the solution cloudy at first? (c) What happens during the few days of waiting?

Copper has compounds with copper(I) ion or copper(II) ion. A compound of copper and chlorine was treated with a solution of silver nitrate, AgNO3, to convert the chloride ion in the compound to a precipitate of AgCl. A 59.40-mg sample of the copper compound gave 86.00 mg AgCl. a Calculate the percentage of chlorine in the copper compound. b Decide whether the formula of the compound is CuCl or CuCl2.

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?

Working with Concentration (Molarity Concepts) Note: You should be able to answer all of the following questions without using a calculator. Part 1: a Both NaCl and MgCl2 are soluble ionic compounds. Write the balanced chemical equations for these two substances dissolving in water. b Consider the pictures below. These pictures represent 1.0-L solutions of 1.0 M NaCl(aq) and 1.0 M MgCl2(aq). The representations of the ions in solution are the correct relative amounts. Water molecules have been omitted for clarity. Correctly label each of the beakers, provide a key to help identify the ions, and give a brief explanation of how you made your assignments. Keeping in mind that the pictures represent the relative amounts of ions in the solution and that the numerical information about these solutions is presented above, answer the following questions c through f. c How many moles of NaCl and MgCl2 are in each beaker? d How many moles of chloride ions are in each beaker? How did you arrive at this answer? e What is the concentration of chloride ions in each beaker? Without using mathematical equations, briefly explain how you obtained your answer. f Explain how it is that the concentrations of chloride ions in these beakers are different even though the concentrations of each substance (compound) are the same. Part 2: Say you were to dump out half of the MgCl2 solution from the beaker above. a What would be the concentration of the MgCl2(aq) and of the chloride ions in the remaining solution? b How many moles of the MgCl2 and of the chloride ions would remain in the beaker? c Explain why the concentration of MgCl2(aq) would not change, whereas the number of moles of MgCl2 would change when solution was removed from the beaker. As part of your answer, you are encouraged to use pictures. Part 3: Consider the beaker containing 1.0 L of the 1.0 M NaCl(aq) solution. You now add 1.0 L of water to this beaker. a What is the concentration of this NaCl(aq) solution? b How many moles of NaCl are present in the 2.0 L of NaCl(aq) solution? c Explain why the concentration of NaCl(aq) does change with the addition of water, whereas the number of moles does not change. Here again, you are encouraged to use pictures to help answer the question.

A 10.00-mL sample of a 24.00% solution of ammonium bromide (NH4Br) requires 23.41 mL of 1.200 molar silver nitrate (AgNO3) to react with all of the bromide ion present. (a) Calculate the molarity of the ammonium bromide solution. (b) Use the molarity of the solution to find the mass of ammonium bromide in 1.000 L of this solution. (c) From the percentage concentration and the answer to part b, find the mass of 1.000 L ammonium bromide solution. (d) Combine the answer to part c with the volume of 1.000 L to express the density of the ammonium bromide solution (in g/mL).