Final answer:
Freezing point depression is preferred over the vapor pressure method in the case of suspected ethylene glycol toxicity because it is a more accurate and reliable technique for determining the concentration of ethylene glycol in a solution.
Step-by-step explanation:
Freezing point depression is preferred over the vapor pressure method in the case of suspected ethylene glycol toxicity because it is a more accurate and reliable technique for determining the concentration of ethylene glycol in a solution. When ethylene glycol is present in the body, it lowers the freezing point of a solution. By measuring the freezing point depression, we can calculate the concentration of ethylene glycol in the solution.
An example of freezing point depression is the use of ethylene glycol in automobile radiators as an antifreeze. The ethylene glycol lowers the freezing point of water, preventing it from freezing and causing damage to the engine.
In contrast, the vapor pressure method relies on the measurement of the vapor pressure of a solution, which can be affected by factors such as temperature and impurities. This makes it less accurate and reliable for determining the concentration of ethylene glycol.