Question

balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. c(s) + h₂(g) → c₂h₆(g)

Explanation:

Step1: Balance Carbon atoms

On the right side, there are 2 C atoms in $\ce{C2H6}$. So, we need 2 C atoms on the left side. Thus, the coefficient for $\ce{C(s)}$ is 2.
$\ce{2C(s) + H2(g) -> C2H6(g)}$

Step2: Balance Hydrogen atoms

On the right side, there are 6 H atoms in $\ce{C2H6}$. Each $\ce{H2}$ molecule has 2 H atoms. Let the coefficient for $\ce{H2(g)}$ be $x$. Then $2x = 6$, so $x = 3$.
$\ce{2C(s) + 3H2(g) -> C2H6(g)}$

Answer:

$\ce{2C(s) + 3H2(g) -> C2H6(g)}$