New Chemistry student.

Question

I'm having some issues understanding the processes and what everything means when it comes to solving problems, if someone could offer some assistance with this question i'd be very grateful.

*How many moles of water are produced when 7.60 moles of propane (C3H8) combust in the presence of oxygen?

C3H8 + 5O2 -> 3CO2 + 4H2O

Answer 1

Hello! The chemical equation of the reaction reveals the answer, as long as it is properly balanced. Since the reaction you have there is properly balanced, you can use the coefficients of each molecule to determine their relationships with each other. If you look at the equation, the coefficient of propane is 1 and the coefficient of water is 4. That tell you that for every 1 mole of propane, you produce 4 moles of water. So if there are 7.6 moles of propane, there will be 30.4 moles water. Use proportions to set it up: 1molC₃H₈/4molH₂O=7.6molC₃H₈/xmolH₂O --> x=(4*7.6)= 30.4molsH₂O