Acompound containing only carbon and hydrogen has a carbon-to-hydrogen mass ratio of 11.89. which carbon-to-hydrogen mass ratio is possible for another compound composed only of carbon and hydrogen?

Answer : or 3.97

Explanation : As the the molar mass of carbon and hydrogen are ;

C=12  g/mol  and  H  =1 g/mol

So, When Carbon Hydrogen mass ratio is 11.89

Then ratio of no. of atoms of C and H is given by   =  

Which will be ≅ 1

So empirical formula C  H  is now possible  

When Carbon Hydrogen mass ratio is taken as 3.97  

The ratio of no. Of atoms of C and H is given by   =  

which gives the answer as

 So empirical formula   is possible

It can be cross verified as ≅ 2.99.

Therefore 3.97 is the correct answer and the empirical formula will be as or