PROBLEM \(\PageIndex{1}\) Explain what changes and what stays the same when 1.00 L of a solution of NaCl is diluted to 1.80 L. The number of moles always stays the same in a dilution. The concentration and the volumes change in a dilution.
PROBLEM \(\PageIndex{2}\) What does it mean when we say that a 200-mL sample and a 400-mL sample of a solution of salt have the same molarity? In what ways are the two samples identical? In what ways are these two samples different? AnswerThe two samples contain the same proportion of moles of salt to liters of solution, but have different numbers of actual moles.
PROBLEM \(\PageIndex{3}\) Determine the molarity for each of the following solutions:
0.679 M Answer b1.00 M Answer c0.06998 M Answer d1.75 M Answer e0.070 M Answer f6.6 M Click here to see a video of the solution
PROBLEM \(\PageIndex{4}\) Determine the molarity of each of the following solutions:
0.9713 M Answer b5.25 × 10-3 M Answer c6.122 × 10-2 M Answer d7.62 M Answer e0.5653 M Answer f1.13 × 10-2 M
PROBLEM \(\PageIndex{5}\) Calculate the number of moles and the mass of the solute in each of the following solutions: (a) 2.00 L of 18.5 M H2SO4, concentrated sulfuric acid 37.0 mol H2SO4 3.63 × 103 g H2SO4 Answer b3.8 × 10−6 mol NaCN 1.9 × 10−4 g NaCN Answer c73.2 mol H2CO 2.20 kg H2CO Answer d5.9 × 10−7 mol FeSO4 8.9 × 10−5 g FeSO4 Click here to see a video of the solution
PROBLEM \(\PageIndex{6}\) Calculate the molarity of each of the following solutions: (a) 0.195 g of cholesterol, C27H46O, in 0.100 L of serum, the average concentration of cholesterol in human serum 5.04 × 10−3 M Answer b0.499 M Answer c9.92 M Answer d1.1 × 10−3 M
PROBLEM \(\PageIndex{7}\) There is about 1.0 g of calcium, as Ca2+, in 1.0 L of milk. What is the molarity of Ca2+ in milk? Answer0.025 M Click here to see a video of the solution
PROBLEM \(\PageIndex{8}\) What volume of a 1.00-M Fe(NO3)3 solution can be diluted to prepare 1.00 L of a solution with a concentration of 0.250 M? Answer0.250 L
PROBLEM \(\PageIndex{9}\) If 0.1718 L of a 0.3556-M C3H7OH solution is diluted to a concentration of 0.1222 M, what is the volume of the resulting solution? Answer0.5000 L Click here to see a video of the solution
PROBLEM \(\PageIndex{10}\) What volume of a 0.33-M C12H22O11 solution can be diluted to prepare 25 mL of a solution with a concentration of 0.025 M? Answer1.9 mL
PROBLEM \(\PageIndex{11}\) What is the concentration of the NaCl solution that results when 0.150 L of a 0.556-M solution is allowed to evaporate until the volume is reduced to 0.105 L? Answer0.794 M Click here to see a video of the solution
PROBLEM \(\PageIndex{12}\) What is the molarity of the diluted solution when each of the following solutions is diluted to the given final volume?
0.125 M Answer b0.04888 M Answer c0.206 M Answer d0.0056 M
PROBLEM \(\PageIndex{13}\) What is the final concentration of the solution produced when 225.5 mL of a 0.09988-M solution of Na2CO3 is allowed to evaporate until the solution volume is reduced to 45.00 mL? Answer0.5005 M Click here to see a video of the solution
PROBLEM \(\PageIndex{14}\) A 2.00-L bottle of a solution of concentrated HCl was purchased for the general chemistry laboratory. The solution contained 868.8 g of HCl. What is the molarity of the solution? Answer11.9 M
PROBLEM \(\PageIndex{15}\) An experiment in a general chemistry laboratory calls for a 2.00-M solution of HCl. How many mL of 11.9 M HCl would be required to make 250 mL of 2.00 M HCl? Answer42.0 mL Click here to see a video of the solution
PROBLEM \(\PageIndex{16}\) What volume of a 0.20-M K2SO4 solution contains 57 g of K2SO4? Answer1.6 L
PROBLEM \(\PageIndex{17}\) The US Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits have been established for a variety of substances, including hexavalent chromium, which is limited to 0.50 mg/L. If an industry is discharging hexavalent chromium as potassium dichromate (K2Cr2O7), what is the maximum permissible molarity of that substance? Answer4.8 × 10−6 M Click here to see a video of the solutionContributors |