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What is the mole fraction of urea, CH4N2O (MM 60 g/mol), in an aqueous solution that is 47% urea by mass? report answer with 3 decimals: X.XXX

User Dubloons
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Answer: The mole fraction of urea in an aqueous solution that is 47% urea by mass is 0.210.

Step-by-step explanation:

Assume we have 100g of aqueous solution.

Then, 47% urea by mass = 47g.

The remaining 53% of the solution by mass is water = 53g.

Molar mass

Urea's molar mass = 60 g/mol

Water's molar mass = 2(1) + 1(16) = 18 g/mol

Number of moles

47g of urea / (60 g/mol) = 0.783 mol urea

53 g of water / (18 g/mol) = 2.944 mol water

Total moles in solution = 3.727 mol

Mole fraction

0.783 mol urea / 3.727 mol = 0.210

User Janus
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