Final answer:
The statement is true; 0.1 M urea shows less depression in freezing point than 0.1 M MgCl2 because MgCl2 dissociates into more particles, creating a greater effect on freezing point depression.
Step-by-step explanation:
The statement that 0.1 M urea shows less depression in freezing point than 0.1 M MgCl2 is true. The phenomenon of freezing point depression is an effect where a solution freezes at a lower temperature than its pure solvent. This is a colligative property, which means it depends on the number of dissolved particles in the solution rather than their identity.
MgCl2 is an ionic compound that dissociates into magnesium ions (Mg2+) and two chloride ions (Cl-), resulting in three particles per formula unit. Hence, a 0.1 M solution of MgCl2 would actually have a higher effective concentration of particles, and would cause a greater depression in the freezing point than the same molarity solution of urea, which does not dissociate into ions. The van 't Hoff factor (i), which represents the number of particles a compound produces in solution, is therefore greater for MgCl2 than urea, increasing the effect on freezing point depression.