Question

Based on the Law of Conservation of Matter, what number should be placed in the box to balance the chemical equation below?



Group of answer choices

No coefficient is needed.

2

4

3

Answer 1

Answer:

2

Explanation:

Step 1: RxN

4Al + 3O₂ → Al₂O₃

Step 2: Balance RxN

We have 4 Al's and 6 O₂'s on the reactant side.

We need the same number of Al's and O₂'s on the product side.

4Al + 3O₂ → 2Al₂O₃

Answer 2

The answer should be 2. Hope this helps :)