Question

What is the weight of urea required in making 2.5 kg of 0.2 molar aqueous solutions??

Answer 1

_/\_Hello mate__here is your answer--

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Molar mass of urea (NH2CONH2)

= 2(1 × 14 + 2 × 1) + 1 × 12 + 1 × 16

= 60 g mol^−1

0.2 molar aqueous solution of urea means:

1000 g of water contains 0.25 mol

= (0.2 × 60)g of urea

= 12 g of urea

That is,

(1000 + 12) g of solution contains 12 g of urea

Therefore, 2.5 kg (2500 g) of solution contains

= (12× 2500)/( 1000+ 12 )

=29.645 g

= 30 g of urea (approximately)

Hence, mass of urea required = 30 g

I hope, this will help you.☺

Thank you______❤

__________________________❤

Answer 2

Hello mate here is your answer -

Molar mass of urea (NH2CONH2) = 2(1 × 14 + 2 × 1) + 1 × 12 + 1 × 16 = 60 g mol−1

0.25 molar aqueous solution of urea means:

1000 g of water contains 0.25 mol = (0.25 × 60)g of urea = 15 g of urea i.e,

(1000 + 15) g of solution contains 15 g of urea

15×2500/1000+15 g

Therefore, 2.5 kg (2500 g) of solution contains = 15×2500/1000+15 = 36.946 g = 37 g of urea (approximately) Hence, mass of urea required = 37 g