The combustion of a gaseous alkane produces 7 L of carbon dioxide plus water vapour. If the original volume of alkane plus oxygen was 6 L, what is the formula of the alkane?
1 Answer
Explanation:
The reaction used is a normal total oxidation of the hydrocarbon by oxygen:
The coefficient for the O_2 is coming from the addition of the ones for the products.
Using the ideal gas formula PV=nRT, where everything is constant but V and n, we can relate both states, before and after the reaction.
where
Then the first side
solving n
Then the formula is
Now, the same result should be obtained from the other side, lets try it out.