Question

al(s) + h₂so₄(aq) → al₂(so₄)₂(aq) + h₂(g)
express your answer as a chemical equation. identify all of the phases in your answer. keep the order of compounds as in the original equation.

Explanation:

Step1: Balance the aluminum atoms

There is 1 Al atom on the left and 2 Al atoms on the right. So, we put a coefficient of 2 in front of Al(s):
$$2Al(s)+H_{2}SO_{4}(aq)\to Al_{2}(SO_{4})_{3}(aq)+H_{2}(g)$$

Step2: Balance the sulfate ions

There is 1 sulfate ion ($SO_{4}^{2 - }$) on the left and 3 sulfate ions on the right. So, we put a coefficient of 3 in front of $H_{2}SO_{4}(aq)$:
$$2Al(s)+3H_{2}SO_{4}(aq)\to Al_{2}(SO_{4})_{3}(aq)+H_{2}(g)$$

Step3: Balance the hydrogen atoms

There are 6 H atoms on the left (from $3H_{2}SO_{4}$) and 2 H atoms on the right. So, we put a coefficient of 3 in front of $H_{2}(g)$:
$$2Al(s)+3H_{2}SO_{4}(aq)\to Al_{2}(SO_{4})_{3}(aq)+3H_{2}(g)$$

Answer:

$$2Al(s)+3H_{2}SO_{4}(aq)\to Al_{2}(SO_{4})_{3}(aq)+3H_{2}(g)$$