A) 1000
B) 1200
C) 1400
D) 1800
Correct Answer: B
Solution :
Key Idea: Osmotic pressure is colligative property. Use the formula\[\pi V=nRT\]to solve problem. \[\pi V=nRT\] Or \[\pi =\frac{n}{V}RT=\frac{mRT}{MV}\] where \[\pi =\]osmotic presure = 600 mm of Hg = 600/760 atm m = mass of solute = 20 g M = molecular mass of solute \[R=0.0821\,L\]atm\[mo{{l}^{-1}}\text{ }{{K}^{-1}}\] \[T=15{}^\circ C=15+\text{ }273=288\text{ }K\] \[V=500mL=0.5L\] \[\frac{600}{760}=\frac{20\times 0.0821\times 288}{M\times 0.5}\] or \[M=1200\] \[\therefore \]molecular mass of solute is 1200.You need to login to perform this action.
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