A very small amount of a $$non-volatile$$ solute (that$$ does not $$dissociate) is dissolved in $$56.8$$ $$cm3$$ of benzene (density$$ $$=$$ $$0.889$$ g $$cm-3). At room temperature vapour pressure of this solution is $$98.88$$ mm Hg while that of benzene is $$100mm$$ Hg. Find the molality of this solution. If the freezing temperature of this solution is $$0.73$$ degree lower than that of benzene, what is the value of molal freezing point depression constant of benzene? (1997-3$$ $$Marks)

Question

A very small amount of a $$non-volatile$$ solute (that$$ does not $$dissociate) is dissolved in $$56.8$$ $$cm3$$ of benzene (density$$ $$=$$ $$0.889$$ g $$cm-3). At room temperature vapour pressure of this solution is $$98.88$$ mm Hg while that of benzene is $$100mm$$ Hg. Find the molality of this solution. If the freezing temperature of this solution is $$0.73$$ degree lower than that of benzene, what is the value of molal freezing point depression constant of benzene? (1997-3$$ $$Marks)

Infinity Learn · Accepted Answer

Po−$$PsPo=xs900$$−$$98.88100=m$$×m.$$w10001.12100=m$$×$$781000m=11.278m=0.143$$Δ$$Tf=kfm0.73=kf0.1435kf=0.730.1435=5.087$$

Want to Fund your own JEE / NEET / Foundation preparation ??

Detailed Solution

Get Expert Academic Guidance – Connect with a Counselor Today!