2. Solved Papers
  3. JAMIA MILLIA ISLAMIA

JAMIA MILLIA ISLAMIA Jamia Millia Islamia Solved Paper-2008

  • question_answer
        Specific rotation of sugar solution is\[~0.5\text{ }deg\text{ }{{m}^{2}}/kg\].\[200\text{ }kg\,{{m}^{-3}}\] of impure sugar solution is taken in a sample polar meter tube of length 20 cm and optical rotation is found to be\[19{}^\circ \]. The percentage of purity of sugar is

    A)  20%                                      

    B)  80%

    C)  95%                                      

    D)  89%

    Correct Answer: C

    Solution :

                    The strength of solution is given by \[c=\frac{\theta }{l\times s}\] Where the symbols have their usual meanings. Here, \[\theta =19{}^\circ ,\text{ }l=20\text{ }cm=0.20\text{ }m,\]                 \[S=0.5\,\deg \,{{m}^{2}}/kg\] \[\therefore \]  \[c=\frac{19}{0.20\times 0.5}=190\,kg-{{m}^{-3}}\] The sugar sample dissolved in a\[{{m}^{3}}\]of water is 200 kg in which 190 kg is pure sugar. Therefore, purity is                 \[\frac{190}{200}\times 100=95%\]


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