Question

c₂h₅oh + o₂ → co₂ + h₂o

Explanation:

Step1: Balance carbon atoms

On the left - hand side, there are 2 carbon atoms in $\ce{C2H5OH}$. On the right - hand side, in $\ce{CO2}$, let the coefficient of $\ce{CO2}$ be \(x\). So, \(x = 2\) (since the number of carbon atoms should be equal on both sides).

Step2: Balance hydrogen atoms

On the left - hand side, there are 6 hydrogen atoms in $\ce{C2H5OH}$. On the right - hand side, in $\ce{H2O}$, let the coefficient of $\ce{H2O}$ be \(y\). Since each $\ce{H2O}$ molecule has 2 hydrogen atoms, \(2y=6\), so \(y = 3\).

Step3: Balance oxygen atoms

On the left - hand side, there is 1 oxygen atom in $\ce{C2H5OH}$ and let the coefficient of $\ce{O2}$ be \(z\). On the right - hand side, there are \(2\times2 + 3\times1=7\) oxygen atoms (from \(2\ce{CO2}\) and \(3\ce{H2O}\)). So, \(1 + 2z=7\), then \(2z=6\), and \(z = 3\).

Answer:

$$\ce{C2H5OH + 3O2 ightarrow 2CO2 + 3H2O}$$