Glucose freezes at -3.75 °C and freezing point of pure water is 0 °C. Thus, depression in freezing point or [tex]\Delta T_{f}[/tex] can be calculated as follows:
[tex]\Delta T_{f}=0-(-3.75)^{o}C=3.75^{o}C[/tex]
It is related to molal concentration as follows:
[tex]\Delta T_{f}=k_{f}m[/tex]
Here, [tex]k_{f}[/tex] is freezing point depression constant.
Rearranging to calculate molal concentration:
[tex]m=\frac{\Delta T_{f}}{k_{f}}=\frac{3.75 ^{o}C}{1.86^{o}C/m}=2.02 m[/tex]
Therefore, molal concentration of glucose in the solution will be 2.02 m.
