Quiz

QUIZ

1. What is the application of Raoult’s law of solutions in non-ideal solutions?

a. It can determine the kinetic energy of the solutes in solution. b. It can determine the actual concentration of solutes in solution. c. It can determine the enthalpy of a solution versus the pure solvent. d. The law cannot be applied to any non-ideal solution.

Answer: d. While Raoult’s law can determine the vapor pressure of a solute as an expression of its mole fraction, this is not true of non-ideal solutions so it cannot be applied to real solutions in chemistry.

2. What is the behavior of the vapor pressure of a solution versus the pure solvent in chemistry?

a. The vapor pressure of a solution will increase with increased solutes in solution. b. The total vapor pressure of the solution will stay the same in a solution versus the pure solvent. c. The total vapor pressure of a solution will decrease versus vapor pressure of the pure solvent. d. There is equal effect on the vapor pressure of different solutes, regardless of their relative concentrations.

Answer: c. The total vapor pressure of a solution will decrease versus the vapor pressure of the pure solvent in solution chemistry.

3. When does Henry’s law fall apart in determining the solubility of a gas in solution?

a. At high pressures b. Before equilibrium c. When gases are reactive with the solvent d. At each of these situations

Answer: d. Henry’s law falls apart and does not apply in high pressure situations, before equilibrium, and when gases are reactive with the solvent.

4. According to Coulomb’s law, what is the relationship between the force of attraction or repulsion between two molecules in relation to their distance between them?

a. Directly proportional to the distance between them b. Inversely proportional to the square of the distance between them c. Directly proportional to the square of the distance between them d. Inversely proportional to the distance between them

Answer: b. The forces between two molecules according to Coulomb’s law is inversely proportional to the square of the distance between them.

5. What will happen to a mixture if the change in enthalpy is large and positive?

a. The mixture will become a solution. b. The mixture will be heterogeneous. c. The mixture will heat up after mixing. d. The mixture will require heating in order to go into solution.

Answer: b. The mixture will be heterogeneous, such as the mixture of oil and water because the enthalpy change will be too large to overcome.

6. You measure a milligram of a solute into a liter of solution. What is the best way to represent this concentration?

a. Moles per liter b. Parts per trillion c. Parts per billion d. Parts per million

Answer: d. In 1 milligram of solute into a liter of solution, there is 1 ppm or one part per million of solute. This makes this a good way to describe this sort of situation in terms of concentration.

7. What is not a colligative property of a solute in a solution?

a. Osmotic pressure b. Vapor pressure elevation c. Boiling point elevation d. Freezing point depression

Answer: b. Each of these is a colligative property of a solute in a solution except for vapor pressure elevation. In actuality, it is vapor pressure lowering that is seen with solutes in solution.

8. Which colligative property of a solute is based on the molarity of the solute versus some other measure of concentration?

a. Boiling point elevation b. Osmotic pressure c. Vapor pressure depression d. Freezing point depression

Answer: b. The osmotic pressure of the solution is based on the molarity of the solute. The molality is used for those colligative properties that are temperature-dependent and the vapor pressure depression is based on the mole fraction of the solute.

9. Which colloidal type is a liquid suspended in another liquid?

a. Sol b. Aerosol c. Foam d. Emulsion

Answer: d. An emulsion is a liquid suspended in another liquid. By definition, this is a colloid that has particles between 1 and 1000 nanometers that does not fall due to gravity if it is stable.

10. Which colloidal type is a solid or liquid particle suspended in a gaseous solvent?

a. Sol b. Aerosol c. Foam d. Emulsion

Answer: b. An aerosol will have a solid or liquid that is suspended in a gas and is typical of aerosols you can think of, such as aerosols in aerosol cans.