Chromic Oxide(Cr2O3) Properties(25 Facts You Should Know)

Chromium oxide is found in nature in the form of the mineral “eskolaite”. Let us see some important facts regarding Chromium oxide.

Chromium oxide is insoluble in water and some organic solvents such as acetone, ethanol, and acids. Other common names of Cr2O3 are chromium sesquioxide, chromium, and chrome green. Cr2O3 is formed from mineral chromite and the decomposition of chromium salt or the exothermal decomposition of ammonium dichromate.

Cr2O3 is used as a catalyst in Butadiene preparation. Let us take a look on various facts such as the IUPAC name, and CAS number ChemSpider ID in this article.

Cr2O3 IUPAC নাম

IUPAC name of Chromium oxide is oxo-(oxochromiooxy) chromium.

Cr2O3 রাসায়নিক সূত্র

Chromium oxide has the chemical formula Cr2O3. In this chromium contain six electrons and oxygen contains six electrons where chromium acquires a +3 charge and oxygen acquires a -2 charge.

Cr2O3 সি.এ.এস. নম্বর

CAS number for Chromium oxide is predicted as 1308-38-9.

Cr2O3 কেমস্পাইডার আইডি

ChemSpider ID for Chromium oxide is 451305.

Cr2O3 রাসায়নিক শ্রেণীবিভাগ

  • Chromium oxide is known as an আয়নিক যৌগ.
  • Chromium oxide is formed by combining chromium metal cation and oxygen non-metal anion.
  • গঠন Chromium oxide representing its ionic property is drawn below.
Structure of Chromium oxide

Cr2O3 পেষক ভর

The molar mass of Chromium oxide is found to be 151.99gm/mol.

Cr2O3 রঙ

Chromium oxide appears light to dark green.

Cr2O3 মোলার ঘনত্ব

The molar density of Chromium oxide is 5.22g/cm3.

Cr2O3 গলনাঙ্ক

The melting point of Chromium oxide is observed at 24350C (4,4150F, 2,708K).

Cr2O3 স্ফুটনাঙ্ক

Chromium oxide boil at 4,0000C (97,2300F, 4,270K).

Cr2O3 ঘরের তাপমাত্রায় অবস্থা

Chromium oxide occurs as solid fine crystals at room temperature.

Cr2O3 আয়নিক বন্ড

একটি আয়নিক ডুরি পাওয়া যায় Chromium oxide compound. On ionization, Chromium oxide gives 2 Cr3+ ions and 3 O2- ions. As chromium is metallic it acquires a positive charge whereas oxygen is non-metallic and contains a negative charge.  

Cr2O3 আয়নিক ব্যাসার্ধ

In chromium oxide ionic radius of Cr3+ is 0.615A0 and of O2- is 1.40A0.

Cr2O3 ইলেক্ট্রন কনফিগারেশন

The arrangement of electrons in a particular shell around the nucleus is known as ইলেকট্রনিক কনফিগারেশন. Let us study the electronic configuration of Cr2O3.

The s, p, d, and f are four orbitals. The electronic configuration of Chromium and Oxygen in chromium oxide is given below.

Cr ⟶ 1s2 2s2 2p6 3s2 3p6 3d5 4s1.

O ⟶ 1s2 2s2 2p4.

Cr2O3 জারণ অবস্থা

Chromium oxide has a +3 oxidation state for chromium and a -2 oxidation state for oxygen.

Cr2O3 অম্লতা/ক্ষারীয়

As Chromium oxide shows both acidic and basic properties, it reflects its এমফোটেরিক nature. In reaction with acid, it behaves like base and in reaction with the base it behaves like acid. Chromium oxide gives hydrated Cr species in reaction with acid, which further gives complex salts in reaction with a base.

Is Cr2O3 গন্ধহীন

Chromium oxide is an odorless powder.

Is Cr2O3 প্যারাম্যাগনেটিক

The presence of unpaired electrons shows পরামৌম্বকত্ব whereas paired electrons show diamagnetic properties. Let us see whether Cr2O3 is paramagnetic or diamagnetic.

Chromium oxide is paramagnetic. In Chromium oxide, each chromium atom contains 3 unpaired electrons thus a total of 6 unpaired electrons which show paramagnetic behavior.

Cr2O3 হাইড্রেট

When Chromium oxide reacts with water it gives hydrate called chromium hydrate. Both Chromium oxide and chromium hydrate have a green color.

Cr2O3 + 3H2O ⟶2Cr(OH)3

Cr2O3 স্ফটিক গঠন

Chromium oxide shows Corundum crystal structure and trigonal R3͞ c (Rhombohedral) space group. In this structure Oxygen atom show hexagonal close-packed packing and the Chromium atom show face-centered cubic packing.

স্ফটিক গঠনক্রিস্টাল সিস্টেমস্পেস গ্রুপ
corundumত্রিকোণR3͞ c
এর স্ফটিক গঠন ক্রোমিয়াম অক্সাইড

Cr2O3 মেরুতা এবং পরিবাহিতা

  • Chromium oxide is a nonpolar compound as Cr2O3 is insoluble in polar solvents such as water. The lattice energy of Cr2O3 is higher than the hydration energy.
  • Chromium oxide show পরিবাহিতা as Cr2O3 contains 6 unpaired electrons which are responsible for conducting electricity due to which it behaves as a strong electrolyte.

Cr2O3 অ্যাসিডের সাথে প্রতিক্রিয়া

Chromium oxide reacts with hydrochloric acid giving the salt of chromium that is chromium chloride and water as a product. This is a type of redox reaction.

Cr2O3 + 6HCl ⟶ 2CrCl3 + 3H2O.

Cr2O3 বেস সহ প্রতিক্রিয়া

Chromium oxide when reacting with a base such as sodium hydroxide gives a chromate ion which is sodium tetrahydroxochromate (II) as a product. This is a redox reaction where Cr in the +3 oxidation state on the reactant side is converted to the +2 oxidation state on the product side.

Cr2O3 + 2NaOH + 3H2O ⟶ 2Na[ Cr(OH)4].

Cr2O3 অক্সাইডের সাথে প্রতিক্রিয়া

Chromium oxide when reacting with oxide in a basic environment undergoes oxidation and gives chromate as a product.

2 ক্র2O3 + 4MO + 3O2 ⟶ 4MCrO4.

Cr2O3 ধাতুর সাথে প্রতিক্রিয়া

Chromium oxide in reaction with metal like aluminum gets reduced to chromium metal and aluminum oxide as a product.

Cr2O3 + 2আল ⟶ 2Cr +Al2O3.


Chromium oxide is a nonpolar compound. Chromium oxide contains two chromium atoms and three oxygen atoms in which each Cr contains a +3 oxidation state and each O contain a -2 oxidation state. In the electric semiconductor, Chromium oxide plays the role of a pigment. It also has an important role to print banknotes and fabrics.

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