Question

What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients?

_____ C₃H₈O(l) + ____ O₂(g) → CO₂(g) + ____H₂O(l)


A) 7
B) 5
C) 9
D) 3

Answer 1

The stoichiometric coefficient for oxygen in the balanced chemical equation of C₃H₈O(l) + O₂(g) → CO₂(g) + H₂O(l) is 5.

Step-by-step explanation:

The stoichiometric coefficient for oxygen when balancing the chemical equation C₃H₈O(l) + O₂(g) → CO₂(g) + H₂O(l) is 5. We can start balancing the equation by looking at the carbons (C), hydrogens (H), and oxygens (O). There are 3 carbons on the left, so we need 3 molecules of CO₂ on the right. There are 8 hydrogens on the left, so we need 4 molecules of H₂O on the right (since it takes 2 H's to make one H₂O). Now count the oxygens: we have 3(2) from the 3 CO₂s and 4 from the 4 H₂Os, totaling 10 oxygens on the right.

Now we need to balance the oxygens on the left. To get 10 oxygens, remembering that O₂ provides 2 oxygens per molecule, we divide 10 by 2, which gives us 5 molecules of O₂. Therefore, the balanced equation is C₃H₈O(l) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(l), and the stoichiometric coefficient for oxygen (O₂) is 5.