Which of the following will exhibit the greatest freezing point depression?
Practice Questions
Q1
Which of the following will exhibit the greatest freezing point depression?
0.1 M NaCl
0.1 M K2SO4
0.1 M CaCl2
0.1 M urea
Questions & Step-by-Step Solutions
Which of the following will exhibit the greatest freezing point depression?
Correct Answer: 0.1 M K2SO4
Step 1: Understand what freezing point depression means. It is the lowering of the freezing point of a solvent when a solute is added.
Step 2: Know that the extent of freezing point depression depends on the concentration of the solute and its ability to dissociate into particles in solution.
Step 3: Identify the van 't Hoff factor (i) for each solute. This factor tells us how many particles the solute breaks into when dissolved.
Step 4: For K2SO4, it dissociates into 2 potassium ions (K+) and 1 sulfate ion (SO4^2-), giving a total of 3 particles. So, its van 't Hoff factor is 3.
Step 5: Calculate the freezing point depression using the formula: ΔTf = i * Kf * m, where ΔTf is the freezing point depression, Kf is the freezing point depression constant, and m is the molality of the solution.
Step 6: Since K2SO4 has a higher van 't Hoff factor (3) compared to other solutes, it will cause a greater freezing point depression at the same molarity.
