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Mole fraction of urea in its aqueous solution is 0.25 .What is the mass of urea present in 200 g urea solution ? (Molecular mass of urea is 60 g `mol^(-1)`) |
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Answer» Correct Answer - Mass of urea present =33.33 g Given : Mole fraction of urea = 0.25 Mass of urea in 200 g solution = ? Mole fraction of water = 1- 0.25 =0.75 Mass of urea = 0.25 `xx 60 =15 g` Mass of water = 0.75 `xx 100 = 75 g` `:.` Mass of solution = 15+ 75 = 90 g `:.` 90 g solution contains 15 g urea `:.200` g solution will contain `(200 xx 15)/(90) ` = 33.33 g urea |
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