J.R. S. answered 02/12/19
Ph.D. University Professor with 10+ years Tutoring Experience
This question is a little vague. I’ll assume you’re looking for the stoichiometric molar ratios in the combustion reaction between butane (C4H10) and oxygen (O2).
2C4H10 + 13O2 ==> 8CO2 + 10H2O. Balanced equation
mole ratio is 2 moles C4H10 to 13 moles O2