Question

c₃h₈ + o₂ → co₂ + h₂o

Explanation:

Step1: Balance carbon atoms

There are 3 carbon atoms in $C_3H_8$. So, the coefficient of $CO_2$ should be 3 to balance the carbon atoms. The equation becomes $C_3H_8+\text{ }O_2
ightarrow3CO_2 + \text{ }H_2O$.

Step2: Balance hydrogen atoms

There are 8 hydrogen atoms in $C_3H_8$. Since there are 2 hydrogen atoms in $H_2O$, the coefficient of $H_2O$ should be 4 to balance the hydrogen atoms. The equation is now $C_3H_8+\text{ }O_2
ightarrow3CO_2 + 4H_2O$.

Step3: Balance oxygen atoms

On the right - hand side, there are $3\times2 + 4\times1=10$ oxygen atoms in $3CO_2$ and $4H_2O$. So, the coefficient of $O_2$ should be 5 to balance the oxygen atoms.

Answer:

1, 5, 3, 4