22.22 gram of urea was dissolved in 300 grams of water. Calculate the number of moles of urea and molality of the urea solution.
(Given : Molar mass of urea = 60 gram `mol^(-1)`)

Explanation

Given, Mass of urea = 22.22 gram
Mass of water = 300 gram
`therefore` No. of mole of urea `= ("Mass of urea")/("Molar mass of urea")`
`=(22.22)/(60)=0.370` moles
Molality (m) = `("Mole of urea")/("Mass of water")xx1000`
`=(0.370)/(300)xx1000`
Molality (m) = 1.23 moles `kg^(-1)` .