Question

A solution of urea is 6 %(by mass)
Calculate the mole fraction of
urea and water is the solution.​

Answer 1

Explanation:

if there is a solution containing two different substances A and B then mole fraction of A or B =moles of A or B /moles of A+B.

we know molar mass of urea= 60g(approx)

so moles of urea =given mass /molar mass = 6/60=0.1.

also 100 ml=100g so, moles of water=100/18=5.55

thus, mole fraction of 6g urea in 100 ml water=0.1/5.55+0.1=0.1/5.65=0.0176.