Answer:
-1.5 °C
Explanation:
The freezing-point depression is a colligative property, that is, the property of a solution. The freezing point of a solution is lower than the freezing point of the pure solvent. We can find the freezing-point depression of a solution of a non-volatile non-electrolyte solute using the following expression.
[tex]\Delta T_f = K_f \times b[/tex]
where,
[tex]\Delta T_f = \frac{1.86\°C}{m} \times 0.82m = 1.5\°C[/tex]
The freezing-point of pure water is 0°C. The freezing-point of the solution is:
[tex]0\°C-1.5\°C = -1.5\°C[/tex]
