Question

A compound 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 1

empirical formula C2H3→ possible
Since the molecular formula of butyne or butadiene C4H6 supports the empirical formula
C2H3

Answer 2

Answer :
`C_(2)H_(3)` 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
`(C)/(H)` =
`(11.89)/(12)/ (1)/(1)`

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
`(C)/(H)` =
`(3.97)/(12)/ (1)/(1)`

which gives the answer as
`(1)/(3)`

So empirical formula
`CH_(3)` is possible

It can be cross verified as
`(11.91)/(3.97)` ≅ 2.99.

Therefore 3.97 is the correct answer and the empirical formula will be as
`CH_(3)` or
`C_(2)H_(6)`