$$10$$% (m/m) aqueous potassium iodide has a density of $$1.202$$ g $$mL-1$$ . The true statements about this solution are

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Infinity Learn · Accepted Answer

$$10$$% solution of Kl contains, $$10$$ g of KI in $$90$$ g (or$$ $$0.09$$ $$kg) of water. Molar mass of KI $$=$$ (39$$ $$+127) g $$mol-1$$ $$=$$ $$166$$ g $$mol-1$$∴molality of $$solution=Number$$ of moles of KIMass of water (in$$ $$kg)                                   $$=10g/166gmol$$−$$10.09kg$$            $$=0.67molkg$$−$$1$$ Further,Molarity (M)=$$ Moles of KI  Volume of $$solution(inL)                                  $$=10g/166gmol$$−$$1$$×$$1000100g/1.202gmL$$−$$1=10/166$$×$$100083.19$$[∵ Volume $$=$$ Mass $$/$$ density $$=100/1.202=83.19mL$$]                                                      $$=0.72molL$$−$$1=0.72M$$ Number of moles of $$KI=10g166gmol$$−$$1=0.06mol$$ Number of moles of water $$=90g18gmol$$−$$1=5mol$$ Mole fraction of $$KI=nKInKI+nH2O$$                                $$=0.065+0.06=0.065.06=0.01186$$

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