J.R. S. answered 11d
Ph.D. University Professor with 10+ years Tutoring Experience
First, write the correctly balanced equation for the combustion of methane (CH4).
CH4 + 2O2 ==> CO2 + 2H2O .. balanced equation
Next, use moles of CH4 combusted, and the mol ratio in the equation to find moles of CO2, and then convert to grams of CO2.
molar mass CH4 = 16 g / mole
molar mass CO2 = 44 g / mol
8.40x10-3 g CH4 x 1 mol CH4 / 16 g = 5.25x10-4 mols CH4
5.25x10-4 mols CH4 x 1 mol CO2 / mol CH4 x 44 g CO2 / mol CO2 = 0.0231 g CO2