Answer:
The correct option is;
D. Calcium chloride breaks into 3 ions, while sodium chloride only breaks into 2 ions
Explanation:
To help melt the ice on icy streets, calcium chloride (CaCl₂) is a more preferred salt type to sodium chloride (NaCl) as when it dissociates into ions in the ice, it forms three ions: a calcium ion, Ca²⁺, and two chloride ions, 2 Cl⁻, while sodium chloride forms two ions: one sodium ion, Na⁺, and one chloride ion, Cl⁻
According to the freezing point depression equation, we have;
ΔT = × m × i
Where;
ΔT = Change in freezing point temperature
= The freezing point depression constant
m = The solution's molality
i = van't Hoff factor
The calcium chloride salt will cause the most depression because the van't Hoff factor is 3 for calcium chloride and 2 for sodium chloride.