Chapter 10 Study Guide - KEY

  1. What is the molarity of a 2.05 L solution that is made by dissolving 27.5 g of sodium chloride in water?
  1. What is the normality of a 6.0 M solution of phosphoric acid?

N = (M)(total pos. ox) = (6.0 M)(3) = 18 N

  1. What is the molality of a solution that is made by dissolving 98.7 g of calcium chloride in 755 g of water?


  1. How many grams of Kl are needed to prepare 325 mL of a 1.33 M solution?
  1. How many grams of NaCl are needed to prepare a 4.15 m solution, using 176 g of water?
  1. Ethyl iodide (C2H5I) boils at 72.5 C and has a density of 1.933 g/mL.
  2. A solution prepared by dissolving 0.300 mol of a nonelectrolyte in 750.0 mL of ethyl iodide boils at 73.5 C. What is the boiling point constant (Kb) for ethyl iodide?

C2H5I = 156.0 g/mol

  1. Another solution is prepared by dissolving 12.5 g of an unknown nonelectrolyte in 100.0 mL of ethyl iodide. The resulting solution boils at 74.9 C. What is the molar mass (molecular weight) of the compound?

  1. What is the freezing point of a solution of 74.2 g of sucrose (C12H22O11) in 883 g of water?
  1. What is the boiling point of a solution of 9.75 g of sodium chloride, an electrolyte, in 115 g of water?
  1. How many grams of sodium chloride, an electrolyte, should be dissolved in 700.0 g of water to produce a solution that freezes at –3.75°C?

  1. A solution was made by dissolving 4.32 g of an unknown covalent solute in 108.5 g of acetone. The solution boiled at 58.75°C. The boiling point of pure acetone is 55.95°C and Kb= 1.71 °C/m. Calculate the molar mass of the solute.
  1. Describe how you would prepare 225.0 mL of a 0.775 M solution of ammonium nitrite starting with
  2. solid ammonium nitrite

NH4NO2

Measure out 11.2 g NH4NO2 and add it to enough water to make 225 mL of solution

  1. 2.25 M ammonium nitrite solution

Measure out 77.5 mL of 2.25 M solution; dilute to a final volume of 225 mL