Question

Calculate the mass of the NH2CONH2 required in
2.25 moles​

Answer 1

Step-by-step explanation:

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