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Calculate the mass of urea `(NH_(2)CONH_(2))` required in making `2.5 kg `of `0.25 `molal aqueous solution. |
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Answer» Correct Answer - `36.945g` `W_(sol)=2.5kg=2.5xx1000g=2500g` `Mw_(2)(NH_(2)CONH_(2))=14+2+12+16+14+2` `=60g mol^(-1)` `W_(1)(` solvent, `H_(2)O)=(W_(sol)-W_(2))=(2500-W_(2))g` `W_(2)=?` Using the formula `m=(W_(2)xx1000)/(Mw_(2)xxW_(1))` `0.25=(W_(2)xx1000)/(60xx(2500-W_(2)))` Solve for `W_(2)` `W_(2)=36.945g` |
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