Manipal Medical Manipal Medical Solved Paper-2015

  • question_answer
    10 mL of water required 1.47 mg of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\](mol. wt. = 294) for oxidation of dissolved organic matter. C.O.D (Chemical Oxygen Demand) of water is

    A) 3.44 ppm                

    B) 24 ppm

    C) 34.4 ppm                

    D) 2.44 ppm

    Correct Answer: B

    Solution :

    10 mL water\[=1.47\times {{10}^{-3}}g\,\,\]of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\] \[{{10}^{6}}\]mL water \[=147\,g\]of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\] \[\because \] 49 g of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\]requires \[{{O}_{2}}=89\] \[\therefore \] 147 g of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\] will required \[{{O}_{2}}=\frac{8\times 147}{49}\]  \[=24\,g\]


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