Question

What mass of carbon dioxide is produced when 7.5g of methane is completely burnt in air.

Answer 1

CH4 + 2O2 ==> CO2 + 2H2O

mols CH4 = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols CH4 to mols CO2.
Now convert mols CO2 to grams CO2. g = mols x molar mass = ?