A chemistry graduate student Is glven 250. mL of a 0.70M acetic acid (HCH,CO,) solution. Acetic acid is a weak acid with K=1.8x 10, What mass of NaCH,CO, should the student dissolve In the HCH,CO, solution to turn It Into a buffer with pH =4.747 2. You may assume that the volume of the solution doesn't change when the NaCH,CO, Is dissolved in It. Be sure your answer has a unit symbol, and round It to 2 significant digits.

A saturated solution of copper(II) iodate in pure water has a copper-ion concentration of 2.7 103 M. a What is the molar solubility of copper iodate in a 0.35 M potassium iodate solution? b What is the molar solubility of copper iodate in a 0.35 M copper nitrate solution? c Should there be a difference in the answers to parts a and b? Why?

An analytical chemist has a solution containing chloride ion, Cl. She decides to determine the amount of chloride ion in the solution by titrating 50.0 mL of this solution by 0.100 M AgNO3. As a way to indicate the endpoint of the titration, she added 1.00 g of potassium chromate, K2CrO4 (see Figure 17.5). As she slowly added the silver nitrate to the solution, a white precipitate formed. She continued the titration, with more white precipitate forming. Finally, the solution turned red, from another precipitate. The volume of the solution at this point was 60.3 mL. How many moles of chloride ion were there in the original solution? How many moles of chloride ion were there in the final solution? You may make any reasonable approximations.

Consider a 2.0-L aqueous solution of 4.17 M NH3, where 21.0 g of NH4Cl are dissolved. To this solution, 4.8 g of CaCl2 are added. (a) What is [OH-] before CaCl2 is added? (b) Will a precipitate form? (c) What is [Ca2+] after equilibrium is established?

How would the solubility of calcium fluoride be affected by the presence of fluoride ion from another source? What is the solubility of calcium fluoride in a saturated solution of barium fluoride? How does this compare with the value of the solubility of calcium fluoride found in Example 17.4? Is this what you expect?

A saturated solution of lead iodate in pure water has an iodate-ion concentration of 8.0 105 M. a What is the molar solubility of lead iodate in a 0.15 M lead nitrate solution at the same temperature? b Should the molar solubility of lead iodate in part a be the same as, greater than, or less than that of lead iodate in pure water? Why?

Lead(II) chromate, PbCrO4, was used as a yellow paint pigment (chrome yellow). When a solution is prepared that is 5.0 104 M in lead ion, Pb2, and 5.0 105 M in chromate ion, CrO42, would you expect some of the lead(II) chromate to precipitate?

A buffer solution is prepared by dissolving 1.50 g each of benzoic acid, C6H5CO2H, and sodium benzoate, NaC6H5CO2, in 150.0 mL of solution. (a) What is the pH of this buffer solution? (b) Which buffer component must be added, and in what quantity, to change the pH to 4.00? (c) What quantity of 2.0 M NaOH or 2.0 M HCl must be added to the buffer to change the pH to 4.00?

Calculate the solubility (in grams per liter) of magnesium hydroxide in the following. (a) pure water (b) 0.041 M Ba(OH)2 (c) 0.0050 M MgCl2

Calculate the solubility of barium sulfate (Ksp = 1.1 1010) in (a) water. (b) a 0.10 M barium chloride solution.