Verified answer

Answer:

0.25 molal aqueous solution of urea means that 0.25 mole of urea are present in 1 kg of water

Moles of urea = 0.25mole

Mass of solvent (water) = 1 kg = 1000 g

Molar mass of urea (NH

2

CONH

2

) = 60 g mol

1. 0.25moleofurea=0.25mol×60gmol1=15g

Totalmassofsolution=1000+15g=1015g=1.015kg

Thus; 1.015 kg of solution contain urea = 15g×2.5kg of solution will require urea

1.015kg

15g

×2.5kg = 37 g

Answer:

0.2! molal aqueous solution of urea means that 0.25 mole of urea are present in 1 kg of water

Moles of urea = 0.25 mole

Mass of solvent ( ater)=1 kg=1000g

Molar mass of urea (N*H_{2}*CON*H_{2}) = 60g

mol

1.0.25moleofurea =0.25 mol*

60gmol * 1 = 15g

Total mass of solution =1000+15g=1015g

Thus; 1.015 kg of solution contain urea:

15g * 2.5kg of solution will require urea (15g)/(1.015kg) * 2.5kg = 37g