The equation for the oxidation or burning of a hydrocarbon is
To find the number of moles of Carbon in the original molecule divide the grams of Carbon Dioxide by the molar mass of Carbon Dioxide.
= 44 grams/ mole
16.4 / 44 = .373 moles of Carbon atoms used.
To find the number of moles of Hydrogen in the original molecule divide the grams of water by the molar mass of Water then multiple the answer by two because there are two atoms of Hydrogen in one molecule of water.
= 18 grams /mole
8.37/ 18.0 = .465 moles of water x 2 = .930 moles of Hydrogen.
Now find the ratio of Hydrogen to Carbon by dividing the number of moles.
.930/ .373 = 2.49 H/C round this off to 2.50 Hydrogen to Carbon.
Since it is not logical to have half an atom multiple the ratio by 2
Let the molecular formula of HC be
And the balanced equation of the combustion reaction of the HC in oxygen is
So by this equation the stochiometric ratio of
But by the given data this ratio is
So equating these two we get
Since the ratio of number of atoms C and H in the HC molecule is