which has biggest change in freezing point among sodium chloride,calcium chloride,and sucrose
The with the most particles in solution. Which would that be?
To determine which compound has the biggest change in freezing point among sodium chloride, calcium chloride, and sucrose, we need to look at their respective properties.
The change in freezing point, also known as freezing point depression, is influenced by the concentration of the solute in a solution. It can be calculated using the formula:
ΔTF = KF × m × i
Where:
ΔTF is the change in freezing point,
KF is the cryoscopic constant (a property of the solvent),
m is the molality of the solute (moles of solute per kilogram of solvent),
and i is the van't Hoff factor (the number of particles solute breaks into in the solution).
To compare the freezing point depression caused by each compound, we need to examine the concentration of the solute and the van't Hoff factor.
1. Sodium Chloride (NaCl):
When NaCl dissolves in water, it dissociates into Na+ and Cl- ions, resulting in two particles (i = 2). Since sodium chloride is a highly soluble compound, it can easily form a concentrated solution with a high molality (m) value.
2. Calcium Chloride (CaCl2):
Calcium chloride also dissociates into three particles when it dissolves in water (i = 3): Ca2+ and two Cl- ions. Like sodium chloride, calcium chloride is highly soluble and can form concentrated solutions.
3. Sucrose (C12H22O11):
Sucrose remains as intact molecules when it dissolves, so it does not dissociate into ions. Therefore, it only adds one particle to the solution (i =1). However, sucrose is less soluble compared to ionic compounds like sodium chloride and calcium chloride.
Based on these considerations, calcium chloride will have the biggest change in freezing point since it dissociates into the highest number of particles (i = 3), allowing it to have a greater effect on the freezing point depression compared to sodium chloride (i = 2) and sucrose (i = 1).