Formulae & Functional Groups

  • O/N 2018/P12/Q35

Which compound has the empirical formula with the greatest relative formula mass?​​ 
A- C2H6

B- C4H10​​ 

C- C5H10​​ 

D- C6H6

Answer:  ​​​​ B

Explaination

The more number of​​ atoms an organic compound has, the greatest relative mass it has. So, first we need to find the empoirical formula of the given compounds, whichever has the greatest number of atoms in it will be considered as eth answer.​​ 

Compound

Empirical Formula

Relative Mass

C2H6

CH3

12+3=15

C4H10​​ 

C2H5

212+5=29

C5H10

CH2

12+2=14

C6H6

CH

12+1=13

 

As we can see from the table above although we don’t need really need to find the relative mass of each, as by the numbers of atom,​​ C4H10​​ is the compound with the greatest number of atoms. ​​