A carbon compound contains 12.8% Carbon, 2.1% Hydrogen, 85.1% Bromine. The molecular weight of the compound is 187.9. Calculate the molecular formula.

Options

A. `CH_(3)Br`
B. `CH_(2)Br_(2)l`
C. `C_(2)H_(4)Br_(2)`
D. `C_(2)H_(3)Br_(3)`

Answer

C

Explanation

Hence, the empirical formula becomes `CH_(2)Br`. Atomic weight of `CH_(2)Br`=12+2+80=94
As we know that `n=("Molecular weight")/("Empirical formula weight")=(187.9)/(94)=2`
Thus, molecular formula =`("empirical formula")_(n)` or Molecular formula=`(CH_(2)Br_(2))=C_(2)H_(4)Br_(2)`