4gm of urea dissolved in 100gm water, the depression in freezing point was found to be 1.24°C calculate the molecular mass of urea?
Answers
Answered by
9
Answer:
Answer:
Molecular mass of urea is near to 60g.
Explanation:
ΔTf =i×Kf×m = Change or depression in freezing point = 1.24
m= molality
Molality = no of moles of solute/ weight of solvent (in Kilogram)
No of moles = 4÷Molecular mass of urea
Urea is a non-electrolyte ,hence vanhoff factor i=1
Therefore
1.24 = Kf×(4÷(Molecular mass of urea×100)) ×1000
Kf of water = 1.86
Implies molecular mass = (1.86×4×1000)÷(1.24×100)
= 60g
Similar questions