Orsat Apparatus

Approximate composition of hydron and methane in producer gas is 10 , 3 % respectively.

Hi I´m not sure if I get the quuestion right, so if my answer doesn´t match with your question please excuse me.

The Orsat gives you the composition of the output product of combustion and if you know the components of your fuel and the amount olf air used (stechiometric or an excess) you now can write the reaction formula:

Fuel + air = Output products

And over this you can perform the reaction balance and using leters for the unknown values you will obtain a lineal equation system, solving it you will find the unknown values and once added to the reaction formula you will know the fuel composition.