the vapour pressure of water is 92mm at 323k . 18.1g of urea are dissolved in 100 g of water the vapour pressure is reduced by 5mm . calculate the molar mass of urea
Answers
Answered by
25
Answer: The molar mass of urea is 60 g/mol
Solution:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
where,
= lowering in vapour pressure= 5 mm
= vapor pressure of pure solvent (water) = 92 mm
= mass of solute (urea) = 18.1 g
= mass of solvent (water) = 100 g
= molar mass of solvent (water) = 18 g/mole
= molar mass of solute (urea) = M g/mole
Now put all the given values in this formula ,we get the vapor pressure of the solution.
Therefore, the molar mass of urea is 60 g/mol
Similar questions