Final answer:
To write the reactant side of a balanced chemical equation for the formation of aluminum sulfate from aluminum and sulfuric acid, we balance sulfate as a unit, then hydrogen, and finish with aluminum, resulting in 2 Al + 3 H₂SO₄.
Step-by-step explanation:
To write the reactant side of a balanced chemical equation for the reaction of aluminum with sulfuric acid to produce aluminum sulfate and hydrogen gas, we start with the unbalanced reaction:
Al + H₂SO₄ → Al₂(SO₄)₃ + H₂
We then begin balancing by focusing on the polyatomic ion (SO₄²⁻) as a whole unit. We change the coefficient of sulfuric acid to balance the sulfate ions:
Al + 3 H₂SO₄ → Al₂(SO₄)₃ + H₂
Next, we balance the hydrogen atoms:
Al + 3 H₂SO₄ → Al₂(SO₄)₃ + 3 H₂
Finally, we balance the aluminum atoms:
2 Al + 3 H₂SO₄ → Al₂(SO₄)₃ + 3 H₂
The balanced reactant side is 2 Al + 3 H₂SO₄. This confirms that all elements are balanced, with the coefficients in the simplest whole-number ratio.