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A solution containing 34.2 g of cane-sugar (C_(12)H_(22)O_(11)) dissolved in 500cm^(3) of water froze at -0.374^(@)C. Calculate the freezing point depression constant of water. |
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Answer» Solution :Here, we have`""DeltaT_(f)=0.374K` CONCENTRATION of sugar solution = 34.2 g in `500 cm^(3)="68.4 in 1000 cm"^(3)="68.4 in 1000 g"` `""(because" density of "H_(2)O="1 g cm"^(-3))` `=(68.4)/(342)" molal"(because "MOLAR mass of "C_(12)H_(22)O_(11)="342 g mol"^(-1))` `=0.2 m` `"APPLYING the relationship"DeltaT_(f)=K_(f)xxm, K_(f)=(DeltaT_(f))/(m)=(0.374 K)/(0.2m)="1.87 K m"^(-1)` |
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