2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-37

  • question_answer
    A 0.5 molal aqueous solution of a weak acid (HX) is 20 per cent ionized. The lowering in freezing point of this solution is (\[{{K}_{f}}=1.86\,K/m\]for water)

    A)  1.12 K       

    B)  -0.56

    C)  0.56 K       

    D)  -1.12K

    Correct Answer: A

    Solution :

    \[\Delta \Tau =i{{K}_{f}}m\] We know, \[\alpha =\frac{i-1}{n-1}\](dissociation) \[\alpha =\frac{i-1}{2-1}\] \[i=\alpha +1\] so \[\Delta {{\Tau }_{f}}=(\alpha +1){{K}_{f}}m\] Given \[\alpha =0.2,\]molality \[=0.5,K_{f}^{'}=1.86\] \[\therefore \]\[\Delta T=0.5\times 1.2\times 1.86=1.116\,K\]


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