Which of the following is the correct empirical and molecular formulae of compound, if the molecular mass of a compound is 80 and compound contains 60% of C, 5% of H and 35% of N?

Options

A. `C_2H_2N,C_4H_4N_2`
B. `C_3H_4N_2,C_6H_8N_4`
C. `C_2H_4N_2,C_4H_8N_4`
D. `C_2H_2N,C_2H_2N`

Answer

A

Explanation

(a) Let 100 g of compound be there
Number of moles of nitrogen`=(35)/(14)=2.5`
number of moles of hydrogen `=(5)/(1.008)=4.9`
number of moles of carbon`=(60)/(12.01)=4.9`
since 2.5 is the smallest value division by it give ratio
`N:H:C`
=1:2:2
empirical formula `=C_(2)H_(2)N`
empirical formula weight=`2xx12+2+14=40`
moleulcar mass=80
molecular formulae=`n(C_(2)H_(2)N)`
`because=2(C_(2)H_(2)N)(n=(80)/(40))=C_(4)H_(4)N_(2)`