A 10% solution (by mass) of sucrose in water has freezing point of 269.15 K. Calculate the freezing point of 10% glucose solution in water, if freezing point of pure water is 273.15 K. Given : (Molar mass of sucrose = "342 g mol"^(-1), molar mass of glucose ="180 g mol"^(-1)).

A 10% solution (by mass) of sucrose in water has freezing point of 269

1.	A 10% solution (by mass) of sucrose in water has freezing point of 269.15 K. Calculate the freezing point of 10% glucose solution in water, if freezing point of pure water is 273.15 K. Given : (Molar mass of sucrose = "342 g mol"^(-1), molar mass of glucose ="180 g mol"^(-1)).
Answer» Solution :`10%` solution in water by mass MENAS 10 g of sucrose is present in 100 g of the solution, i.e., Solute (sucrose) = 10 g, solvent (water) = 90 g `M_(2)=(1000K_(f)w_(2))/(w_(1)xxDeltaT_(f))` `"or"K_(f)=(M_(2)xxw_(1)xxDeltaT_(f))/(1000xxw_(2))=(342xx90xx(273.15-269.15))/(1000xx10)="12.312 K kg mol"^(-1)` `10%` of glucose solution in water means `w_(2)=10, w_(1)=90g` `DeltaT_(f)=(1000K_(f)w_(2))/(w_(1)M_(2))=(1000xx12.312xx10)/(90xx180)=7.6^(@)` `THEREFORE"FREEZING point of solution "= 273.15 - 7.6=265.55 K`