Question

what will be boiling point of o.1 m urea (as)
solution ( kb= 0.52 K kg mol )​

Answer 1

Answer:

As we know that, depression in boiling point,

ΔTb=kb.m

where,

ΔTb = Elevation in boiling point = 0.52

kb = molal elevation of boiling point = 0.52

m = molality of solution = ?

∴0.52=0.52×m

⇒m=1

As,

m=Kg of solventmoles of solute=1

⇒ As the molality is 1, it signifies that 1 mole of urea is present in 1 kg of water.

∴ no. of moles of water in the solution = 181000=55.55;(∵ 18 is the molar mass of water)

As we know,

mole fraction of solute or solvent in the solution = total no. of moles of solutionno. of moles of solute or solvent

∴ mole fraction of urea in water =total no. of molesno. of moles of urea in the solution

⇒ mole fraction of urea in water =1+55.551=56.551=0.0176≈0.018

Hence, the mole fraction of urea in the solution is 0.018.

I hope it is right