Question 6

Balance the following the chemical equation:

Al + O2 → Al2O3

Blank 1:
Blank 2:
Blank 3:

1 answer

To balance the chemical equation for the reaction of aluminum (Al) with oxygen (O₂) to form aluminum oxide (Al₂O₃), we need to ensure that the number of atoms of each element on the reactant side is equal to the number on the product side.

The unbalanced equation is:

\[ \text{Al} + \text{O}_2 \rightarrow \text{Al}_2\text{O}_3 \]

  1. Count the number of atoms for each element:

    • On the left side (reactants), we have:
      • Aluminum (Al): 1
      • Oxygen (O): 2 (from O₂)
    • On the right side (products), we have:
      • Aluminum (Al): 2 (from Al₂O₃)
      • Oxygen (O): 3 (from Al₂O₃)
  2. Balance the Aluminum: We need 2 Al atoms on the left side to match the 2 Al atoms on the right side. We can do this by putting a coefficient of 2 in front of Al:

\[ 2 \text{Al} + \text{O}_2 \rightarrow \text{Al}_2\text{O}_3 \]

  1. Balance the Oxygen:
    • Now on the left side we still have O₂ (which provides 2 O atoms), and on the right side we have 3 O atoms in Al₂O₃. To balance the oxygen, we need to find a common multiple.
    • The least common multiple of 2 (from O₂) and 3 (from Al₂O₃) is 6, so we will need 3 O₂ on the reactant side to give us 6 O atoms, and we will need 2 Al₂O₃ on the product side to give us 6 O atoms as well.

Putting this all together, the coefficients we need are:

\[ 4 \text{Al} + 3 \text{O}_2 \rightarrow 2 \text{Al}_2\text{O}_3 \]

Therefore:

  • Blank 1: 4
  • Blank 2: 3
  • Blank 3: 2

So the balanced equation is:

\[ 4 \text{Al} + 3 \text{O}_2 \rightarrow 2 \text{Al}_2\text{O}_3 \]