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Aluminium and oxygen

Balance Al + O₂ → Al₂O₃

4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)

  • Combination reaction
  • 4 : 3 : 2 coefficients

Balance an equation

Arrow. Type -> or =. Subscripts. Plain digits: H2SO4, Ca(OH)2, CuSO4.5H2O. Charges. Fe3+, OH-, SO4 2-, and e- for an electron. States. (s), (l), (g) and (aq) are kept. Coefficients you type are checked.

4Al(s)+3O₂(g)→2Al₂O₃(s)

Balanced

Atoms on each side

AtomAs writtenleft : rightBalancedleft : right
Al1:24:4
O2:36:6

Check atoms

How to balance it
Working

How to balance it, step by step

  1. Count the atoms of each element on both sides, as written.
  2. Start with the biggest formula, Al₂O₃: put 1 in front of it.
  3. Al: 2 on the right. Put 2 in front of Al.
  4. O: 3 on the right. Put 3/2 in front of O₂ (3/2 × 2 = 3).
  5. Clear the fraction: multiply every coefficient by 2.
  6. Check: Al 4 = 4, O 6 = 6. Balanced.
The reaction

What happens

It is a combination reaction: two or more substances join to form a single product. Aluminium forms a thin layer of aluminium oxide in air, which protects the metal underneath from further corrosion.

Questions

Aluminium and oxygen: quick answers

What is the balanced equation for aluminium and oxygen?

4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s). The coefficients are 4, 3 and 2. Each side then has 4 Al and 6 O.

What type of reaction is aluminium and oxygen?

It is a combination reaction: two or more substances join to form a single product. Aluminium forms a thin layer of aluminium oxide in air, which protects the metal underneath from further corrosion.

How do you balance Al + O₂ → Al₂O₃?

Start with the biggest formula, Al₂O₃: put 1 in front of it. Al: 2 on the right. Put 2 in front of Al. O: 3 on the right. Put 3/2 in front of O₂ (3/2 × 2 = 3). Clear the fraction: multiply every coefficient by 2. Never change a subscript, because that would change the substance.

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