MHT CET202120 Sep 2021Morning ShiftChemistrySolutionsActual
What is cryoscopic constant of water if 5 ~g of glucose in 100 ~g of water has depression in freezing point 2.15 ~K ? (Molar mass of glucose =180 )
Options
- A7.74 ~K ~kg ~mol ⁻¹
- B0.52 ~K ~kg ~mol ⁻¹
- C1.32 ~K ~kg ~mol ⁻¹
- D3.86 ~K ~kg ~mol ⁻¹
Correct answer
A. 7.74 ~K ~kg ~mol ⁻¹
Step-by-step solution
aligned & T _ f = kf m & m ( molality )= moles of glucose massof water ( kg ) & m = 5 / 180 0.1 ~kg = 5 18 ~mol / kg & T _ f =2.15 ~K & 2.15= K _ f 5 18 & ~K _ f =7.74 ~K ~kg ~mol aligned