Solutions

  1. A 1.0 m solution of biphenyl (C12H10) in cyclohexane has a density of 1.10 g/mL.
    1. Calculate the molarity, weight percent, and mole fraction of the solution.
    2. Calculate the freezing point of the solution.
    3. Biphenyl is a planar molecule with two benzene rings attached through one C-C bond. What kinds of intermolecular forces are present in the solution?
  2. Classify each of the following as strong, weak or non electrolytes.
    1. 2-propanol
    2. propanoic acid
    3. n-propyl amine
    4. barium chloride
    5. nitrous acid
  3. A compound contains carbon, hydrogen, oxygen, and chlorine. When 13.3 g are dissolved in 500 g water, the resulting solution has a freezing point of -0.36 °C. The solution weakly conducts electricity because of a proton transfer reaction.
    1. Determine the molecular weight of the compound (Kf = 1.8).
    2. Assume that a molecule of the compound contains two carbons and two oxygens. Determine how many chlorines and hydrogens are also present and write a possible structural formula for the compound.
  4. A 0.050 molal solution of CH3COOH (acetic acid) in cyclohexane has a density of 0.90 g/mL.
    1. Calculate the molarity of the solution.
    2. Calculate the weight percent of the solution.
    3. Calculate the freezing point of the solution.
    4. Draw an energy level diagram showing the energy of the solute and solvent relative to the energy of the solution. Show DH on the diagram and indicate whether it is positive, negative, or zero.
  5. Iodine is fairly soluble in CCl4. Analyze the forces between particles in the solute, solvent, and solution and explain why I2 is soluble in CCl4.