3 Facts on Cr2O3 + H2O: What, How to Balance

Facts on Cr2O3 + H2O are the resources, which can produce viable knowledge about some chemical reactions, happened in chemistry.

The reaction type of this specific reaction and its balancing equation would be represented broadly in this article. Those facts would be derived in this article and those are being listed below:

  • What is Cr2O3 + H2O
  • What is the product of Cr2O3 + H2O
  • How to balance Cr2O3 + H2O
  • What type of reaction is Cr2O3 + H2O

What is Cr2O3 + H2O

The combination of water molecule with chromium oxide is called chromium hydrate. Chromium oxide is an oxide with green colour amorphous structure that is basically used as pigment. This inorganic compound has a different name that is chromia.

In the aqueous state of Chromia it has been identified that the compound is found to be stable one with blue to green colour. After combining with water molecule the compound with 3+ oxidation that indicates its transition of electrons in the inner structure.

cr2o3 + h2o
Chromium oxide from Wikipedia

Therefore, the hydrate state of Chromium dioxide is represented with the chemical formula of Chromium dioxide and water. Volatilisation reaction is noticed to take place when Cr2o3 comes contact with H2O and O2.

This reaction is recognised to happen in an early stage of oxidation of chromium. However, the evaporation of the product of this reaction imposes a different angle of viewpoint about the reaction. 

What is the product of Cr2O3 + H2O?

In aqueous solution after reacting with water Chromium dioxide gives out a different kind of product with different organic group.

The product of reaction between Chromium dioxide and water is 2Cr(OH)3 that is Chromium hydroxide. The product is insoluble in water and it is a polymer that has an undefined structure.

cr2o3 + h2o
Cr2O3 +H2O product from Wikipedia

However, the compound is quite different from the parent compounds but both of Cr2O3 and 2Cr(OH)3 have green colour. The density of Chromium oxide is decreased after getting water molecule in its structure. The density of Cr2O3 is found as 5.22 g/cm3 and the density of chromium hydroxide is 3.11 g/cm3.

In the reaction, the evaporation rate of Cr2O3 is found to be higher than the growth rate of the same compound. The degradation of the Cr2O3 scale is the main factor  that is noticed in high rate in the reaction.

How to balance Cr2O3 + H2O

Systematic balancing the overall equation is the fact which helps to demonstrate the balancing the reaction regarding reactants and products. Equation balancing is efficient in providing the note about participation of elements in the reaction with exact amount.

The steps would include the balance of number of molecules of each element participate in the reaction that are Chromium, Hydrogen and Oxygen.

Step 1: Balancing the number of Chromium molecules

The Number Chromium Molecules is noticed to take place in Cr2O3 is two as reactant; therefore, it is much important to extract two Chromium with the extraction of product. The formula of Chromium hydroxide is recognised to hold only one Chromium molecule. It is important put two as variable of the product to balance Chromium.

Cr2O3 + H2O  = 2Cr(OH)3

Step 2: Balancing the number of Hydrogen molecules

Two Hydrogen molecules of water are identified to deliver the product. Therefore, the number of hydrogen should be two in product but the number of Hydrogen molecules held by Chromium hydroxide is three. Therefore, the total number of hydrogen molecule in product becomes (2*3) = 6.

Cr2O3 + 3H2O  = 2Cr(OH)3

In this case, it becomes significant to provide variable of three to the reactant water molecule that create equivalent number of reactant hydrogen and product hydrogen.

Step 3: Balancing the number of Oxygen molecules

The number of oxygen that is present in Chromium oxide is three. And in balancing the number of hydrogen molecule we put determined that three water molecule reacts with Chromium oxide, hence; the number of oxygen molecule in reactant is found to be 6 and the previous equation is representing the same oxygen molecule present in product as well.

Cr2O3 + 3H2O = 2Cr(OH)3

Step 4: Preparing the whole equation

The final balanced equation has recognised in the previous step that denotes that one Chromium oxide molecule and three water molecules react with each other to form two chromium hydroxide molecules.

What type of reaction are Cr2O3 + H2O

Evaporation of Cr2O3 is noticed to take place in the chemical formation of its viable products. In the early stage of oxidation Cr2O3 reacts with water and significantly indicates the degradation of Cr2O3 scale by the evaporation of this compound.

This reaction is a mixed type of evaporation, degradation and volatilisation reaction. The chemical reaction can be highlighted as:

½ Cr2O3 (s) + ¾ O2 (g) + H2O (g) = CrO2(OH)2(g)

cr2o3 + h2o
Structure of Cr2O3 from Wikipedia

Therefore, evaporation is then fundamental process that is undertook by the main reactant here. Besides, volatilisation of Cr2O3 scale is the core method that comparably expresses a different kind of reaction type for Chromium oxide in presence of oxygen and water vapour.


This article has created broad knowledge about the reaction between Chromium oxide and water. Hence, the properties of aqueous solution of Chromium oxide has been reflected in this article that can be concluded with better outcomes on the study on product the reaction gives.

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