Question

It was determined that 1.4 x 1024 carbon dioxide molecules are produced when propane is combusted according to the equation below. Calculate the number of moles of propane that was burned.C 3H 8 + 5O 2 ----> 3CO 2 + 4H 2O

Answer 1

First, we have to convert the number of molecules to the number of moles of CO2 (carbon dioxide), and to do this we can do the Avogadro's number:

The Avogadro's number helps us to determine the number of moles based on the number of molecules or atoms of a compound. This number is 6.022 x 10 ^(23) /mol.

So, the conversion from molecules to moles would be:

`1.4\cdot10^(24)moleculesCO_2\cdot(1molCO_2)/(6.022\cdot10^(23)moleculesCO_2)=2.325molCO_2.`

Now, using this data we can calculate the number of moles needed for propane (C3H8).

In the chemical reaction, you can see that 1 mol of propane produces 3 moles of CO2, so the calculation would be:

`2.325molCO_2\cdot(1molC_3H_8)/(3molesCO_2)=0.775molC_3H_8.`

The answer is that 0.78 moles of C3H8 were burned and produced 2.325 moles of CO2 which is 1.4 x 10 ^(24) molecules of CO2.