Molarity defines the concentration of a solute in a solution using the units of moles/liter. A 1M solution is defined as 1 mole of solute/1 liter of solution.

Molarity problems can be readily solved by simple algebra or by the factor unit method. Once again, the factor unit method is the better choice for most students.

· How many grams of NaCl are required to prepare 500 mL of 0.15 M NaCl solution? The formula mass of NaCl is 58.5 amu. What is the first step in solving this problem? J

· How many grams of HCl are found in 500 mL of stomach acid if the concentration of stomach acid is 0.10 M HCl? (It is probably a little higher than this during exams. L ) The formula mass of HCl is 36.5 amu. What is the first step in solving this problem? J

· How many milliliters of a 2.0 M H2SO4 solution would be required to react completely with 20 g of NaOH? The formula mass of H2SO4 is 98.1 amu and the formula mass of NaOH is 40.0 amu.

H2SO4 + 2 NaOH ® Na2SO4 + 2 H2O

What is the first step in solving this problem? J

Return to the problem tutorial. J

Copyright © August 2000 by Richard C. Banks...all rights reserved.