Let's begin by writing the balanced chemical equations:
Then we calculate the number of moles in 97g of propane.
n(propane)=
According to the balanced chemical equation, one mole of propane produces 3 moles of carbon dioxide. So the available number of moles of propane must be multiplied by three to work out the number of carbon dioxide produced.
Use a balanced equation to determined quantity of carbon and hydrogen. Then use simple division to determine the empirical formula before the molecula formula