Create an account to track your scores
and create your own practice tests:
Test: MCAT Physical
Boiling point is the temperature a liquid needs to achieve in order to begin its transformation into a gaseous state. Campers and hikers who prepare food during their trips have to account for differences in atmospheric pressure as they ascend in elevation. During the ascent, the decrease in atmospheric pressure changes the temperature at which water boils.
Further complicating the matter is the observation that addition of a solute to a pure liquid also changes the boiling point. Raoult’s Law can be used to understand the changes in boiling point if a non-volatile solute is present, as expressed here.
In this law, is the mole fraction of the solvent, is the vapor pressure of the pure solvent, and is the vapor pressure of the solution. When this vapor pressure is equal to the local atmospheric pressure, the solution boils.
1. | A scientist is studying boiling point changes with the addition of solutes, and creates a colloid. A colloid is similar to a solution because both will possess which of the following characteristics? I. They both show the Tyndall effect on light II. They both involve the suspension of only molecular-sized particles III. They both involve the suspension of particles that are too small to be individually distinguished with the naked eye |
II and III
I and II
I and III
III, only
I, II, and III
Certified Tutor