Question

what mass of 0.5 molal urea solution contains 0.15 mole urea

Answer 1

Molality of a solution is calculated in the following way:

       molality = moles of solute/ kg of solvent
                     
       Therefore mass of solvent =molality/moles

Molality = 0.5 molal
Moles = 0.15 moles

Thus,   mass    =   0.5/0.15

                        = 3.33 kg

Therefore the mass of 0.5 molal urea that contains 0.15 moles is 3.33 kg urea

Answer 2

it's 309gram .

9g of urea in 0.15 mole of ureA +mass solvent of 0.5 molal solution having .0.15 mole urea which if 300 .

300 + 9 =309.

hope this will help you ..