2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main - Mock Test - 10

  • question_answer
    In an experiment, \[4\text{ }g\] of \[{{M}_{2}}{{O}_{x}}\] oxide was reduced to \[2.8\text{ }g\] of the metal. If the atomic mass of the metal is \[56\text{ }g\text{ }mo{{l}^{-1}},\] the number of O atoms in the oxide is

    A) 1                                 

    B) 2       

    C) 3                     

    D) 4

    Correct Answer: C

    Solution :

     \[{{M}_{2}}{{O}_{x}}\xrightarrow{\operatorname{Re}duction}M\]
    Eq. of \[{{M}_{2}}{{O}_{x}}=\] eq. of Metal
    \[\frac{Wt\,\,of\,\,{{M}_{2}}{{O}_{x}}}{Eq.\,wt.\,of\,{{M}_{2}}{{O}_{x}}}=\frac{Wt.\,of\,Metal}{Eq.\,wt.\,of\,Metal}\]
    \[\frac{4}{\frac{2\times 56+x\times 16}{2x}}=\frac{2.8}{\frac{56}{x}}\]
    On solving we get,
    \[\Rightarrow \,\,\frac{4}{56+8x}=\frac{2.8}{56}\Rightarrow \frac{1}{14+2x}=\frac{1}{20}\Rightarrow 2x=6\Rightarrow x=3\]Hence, the oxide is \[{{M}_{2}}{{O}_{3}}\].


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