InterviewSolution
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InterviewSolution
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What is the freezing point of a solution containing 8.1 g HBr in 100g water assuming the acid to be 90% ionised (`K_(f)` for water `= 1.86 "Kg mole"^(-1)`)A. `0.85^(@)C`B. `-3.53^(@)C`C. `0^(@)C`D. `-0.35^(@)C` |
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Answer» Correct Answer - B `{:(HBr,hArr,H^(+),+,Br^(-)),((1-alpha),,alpha,,alpha):}` Total `= 1+alpha therefore i=1+alpha=1+0.9=1.9` `Delta T_(f)= i K_(f)xx m=1.9xx1.86xx(8.1)/(81)xx(1000)/(100)=3.53^(@)C` `T_(f)=-3.53^(@)C`. |
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