Which of the following results from the presence of a solute in a given solvent?
A. The vapor pressure of the solution is lower than that of the pure solvent.
B. The boiling point of the solution is lower than that of the pure solvent.
C. The freezing point of the solution is higher than that of the pure solvent.
D. all of the above
D is incorrect.
A is right.
B is wrong
C is wrong
D is worng
To determine which of the options is correct, we need to understand the concept of colligative properties.
Colligative properties are physical properties of a solution that depend on the concentration of solute particles, regardless of the nature of the solute itself. In other words, these properties are affected by the number of solute particles, not their specific identity.
Now let's evaluate each option:
A. The vapor pressure of the solution is lower than that of the pure solvent:
When a solute is added to a solvent, the presence of solute particles restricts the evaporation of solvent molecules. This results in a decrease in the vapor pressure of the solution compared to that of the pure solvent. Thus, option A is correct.
B. The boiling point of the solution is lower than that of the pure solvent:
The boiling point of a liquid is the temperature at which its vapor pressure equals the atmospheric pressure. When a solute is added to a solvent, it increases the boiling point of the solution. This is because the presence of solute particles reduces the evaporation of solvent molecules, making it more difficult for the solution to reach its boiling point. Therefore, option B is incorrect.
C. The freezing point of the solution is higher than that of the pure solvent:
When a solute is added to a solvent, it disrupts the formation of solvent's crystal lattice during freezing. This leads to a decrease in the freezing point of the solution compared to that of the pure solvent. Thus, option C is incorrect.
Given the explanation above, the correct answer is option A.