2. Solved Papers
  3. CET Karnataka Engineering

CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2004

  • question_answer
    Specific rotation of sugar solution is units. \[200\text{ }kg{{m}^{-3}}\] of impure sugar solution is taken in a polarimeter tube of length 0.25 m and an optical rotation of 0.4 rad is observed. The percentage of purity of sugar in the sample is:

    A)  11%                                      

    B)  20%

    C)  80%                                      

    D)  89%

    Correct Answer: C

    Solution :

    Specific rotation of sugar solution is                                 \[\alpha =\frac{angle\text{ }of\text{ }rotation}{length\text{ }of\text{ }tube\times concentration}\]                 \[=\frac{\theta }{l\times C}\] \[\therefore \]  \[C=\frac{\theta }{l\,\,\alpha }\]                 \[=\frac{0.4}{0.25\times 0.01}\]                 \[=160\,\,kg/{{m}^{3}}\] Thus, purity of sugar solution                 \[=\frac{1600}{200}\times 100=80%\]


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