2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-22

  • question_answer
    If 20 g of a solute was dissolved in 500 ml of water and osmotic pressure of the solution was found to be 600 mm of Hg at \[15{}^\circ C\] , then molecular weight of the solute is

    A)  900               

    B)       1200  

    C)       1100              

    D)       1600              

    Correct Answer: B

    Solution :

    Here, osmotic pressure \[(\pi )=660\,mm\]of Hg = 600/760 atm. Temperature \[(T)=15{{\,}^{o}}C=15+273=288\,K\] Weight of solute (m) = 20 g Volume (V} = 500 ml = 0.5 litre Molecular weight (M)=? \[R=0.0821\,\text{L}\,\text{atm}\,\text{mo}{{\text{l}}^{-3}}{{\text{K}}^{-1}}\] On using\[\pi V=nRT\] \[\pi =\frac{n}{V}\] \[RT=\frac{m/MRT}{V}\] \[\frac{600}{760}=\frac{20}{M}\times \frac{0.0821\times 288}{600/760\times 0.5}\] \[M=1200\] Hence, the correct option is (b).


You need to login to perform this action.
You will be redirected in 3 sec spinner