3 Facts on cr2o3 + al :What,How To Balance

In this article, we will study the reaction between chromium oxide and aluminium cr2o3 + al , how to balance it, and the characteristics of this reaction.

Chromium oxide is a green-colored inorganic compound with the chemical formula Cr2O3. Aluminium belongs to group 13 and has the chemical symbol Al.

What is cr2o3 + al?

This is a reaction between chromium(III) oxide and aluminium. It produces chromium and aluminium oxide and occurs at 800 C. This reaction is a type of the alumino thermite reaction. In this reaction, aluminium acts as a reducing agent. The oxides of chromium, iron, etc., are converted to their corresponding metals. In this case, chromium(III) oxide is reduced to chromium. It is an exothermic reaction.

cr2o3 + al
Cr2O3 Structure

What is the product of Cr2O3 + Al?

Aluminium is a reducing agent- the chemical species that gets oxidized by losing electrons. It loses six electrons to form Al3+; 2Al0 – 6 e → 2AlIII. Cr2O3 is an oxidizing agent-the chemical species that gets reduced by gaining electrons. Chromium oxide gets reduced by gaining six electrons; 2CrIII + 6e → 2Cr0. This is a redox reaction where oxidation and reduction happen simultaneously. The final products formed are aluminium oxide-Al2O3 and chromium metal, Cr.

How to balance cr2o3 + al?

The law of conservation of matter states that mass can neither be created nor be destroyed. Balancing chemical equations is based on this law. In a chemical reaction, there are reactants on the left side of the equation and products on the right side of the equation.

Cr2O3 + Al → Al2O3 + Cr; this is the equation that we will balance. To balance the chemical equation, we need to identify the atoms in the reaction and ensure that each atom is present in the same number on the reactant and product side.

               Atom Number in reactants Number in products
                 Cr                    2                    1
                  O                    3                    3
                  Al                    1                    2

Now we will multiply the atoms by coefficients to balance the equation. Coefficients are whole numbers we will place in front of the element or compound. It indicates how many units of each element participate in the reaction.

Starting with chromium, there are two atoms of chromium in the reactant and one on the product. We will place two as a coefficient in front of Cr on the product side. Cr2O3 + Al → Al2O3 +2Cr; there are two chromium atoms on both reactant and product sides; therefore, chromium is balanced.

There is one aluminium atom in the reactant and two in the product. We will place a coefficient of two in front of aluminium and balance it. Cr2O3 +2Al → Al2O3 +2Cr; all the atoms on reactants and products are the same, making this equation balanced(two chromium atoms, two aluminium atoms, and three oxygen atoms on both sides).

What type of reaction is cr2o3 + al?

Cr2O3 + Al is a redox reaction in which aluminium is a reducing agent and Cr2O3 is an oxidizing agent. It is also an exothermic reaction that releases energy into the surroundings.


The reaction of chromic oxide with aluminium gives chromium metal and aluminium oxide. It is a redox reaction where aluminium acts as a reducing agent and Cr2O3 as an oxidizing agent. It is an exothermic reaction with a Gibbs free energy value of -421KJ/mole. In this article we learned, how to balance Cr2O3 + Al → Al2O3 + Cr and the characteristics of this reaction.

Sakshi Anand

Hello, I am Sakshi Anand and I am here to make chemistry easy and enjoyable to read. Complex ideas do not require complex language. I am an avid reader and enjoy researching intensively.

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