C3H8 +________O2 ---------3CO+4H2O . Which is the balance the reaction
A. 1
B. 7
C. 5
D.3
If you had to balance this equation as it is, then the coefficient of O2 would be (7/2), since there are seven O atoms on the right.
However, the correct equation of the combustion of propane (C3H8) is:
C3H8 + _____O2 ---------> 3CO2 + 4H2O
(That is, CO2 in place of CO)
In this case, there are ten O atoms on the right side, and hence 5 molecules of O2 are required.
So, the answer is (C)
To balance the given chemical equation, C3H8 + ________O2 -> 3CO + 4H2O, you need to determine the coefficient for O2.
To balance the equation, you should start by counting the number of atoms on each side of the equation. In this case, as the equation is unbalanced, it is likely that the O2 molecule needs to be adjusted.
In the reactant side, there are 3 carbon atoms, 8 hydrogen atoms, and 2 oxygen atoms (from the C3H8 molecule). On the product side, there are 3 carbon atoms, 8 hydrogen atoms, and 8 oxygen atoms (from the 3CO and 4H2O molecules, respectively).
Since oxygen is the only element with a different number of atoms on each side, we should focus on balancing the oxygen atoms.
By comparing the number of oxygen atoms, we can see that there are 2 oxygen atoms in the reactant side (from C3H8) and a total of 8 oxygen atoms on the product side (from 3CO and 4H2O). To balance the oxygen atoms, we need to add 6 more oxygen atoms to the reactant side.
To add 6 oxygen atoms, we can multiply the O2 molecule on the reactant side by 3:
C3H8 + 3O2 -> 3CO + 4H2O
By doing this, the number of oxygen atoms on each side is now equal.
So the balanced chemical equation is C3H8 + 3O2 -> 3CO + 4H2O.
Thus, the correct answer is:
D. 3