| Q: | Which of the following are examples of colligative properties? I. freezing point depression II. osmotic pressure III. boiling point elevation |
| A | III only | |
| B | I and III only | |
| C | I only | |
| D | I, II and III |
The correct answer is D. This question asks about colligative properties, which is dependent on the solute/solvent ratio, and not dependent on the identity of the solute. I thought of colligative as similar to collaborate and coagulate, both of which affect the ratios of individual objects. When concentration is higher, then osmotic pressure is definitely effected. For example, is more of a solute like sodium is dissolved in extracellular fluid, then the osmotic pressure on the cell changes, creating a hypertonic situation. This automatically eliminates all answer choices other than D. Freezing point depression and boiling point elevation are similar and can be thought of in terms of the example of salt (solute) dissolved in water (solvent). Changing the amount of solute in this case would both lower the freezing point of the solution as well as elevate the boiling point of water.