Cr2o3 Lewis Structure,Characteristics:21 Facts You Should Know

In this article we want to discuss about cr2o3 lewis structure, characteristics and 21 most important characteristics regarding this topic.

Cr2o3 is mainly used in color industry which acts as a pigment. It is generally insoluble in water and it is an amphoteric oxide. Naturally it occurs as a dark green and hexagonal crystalline solid. For the preparation of chromium metal, for polishing of stainless steel cr2o3 is largely used.

Cr2o3 Lewis Structure Drawing

In cr2o3, out of 3 o atoms 1 o atom is shared both by cr atoms by covalent sigma bonds. 2 cr atoms forms 1 sigma and 1 pi bonds with o atoms.

The whole molecule is arrangd in a tetrahedral manner in which central o atom forms 2 bond with 2 cr atoms and it contains 2 lone pair and in all aspect all these bonds are purely covalent and formed by sharing of electrons. In cr2o3, terminal o atoms contain 2 lone pairs each.

Cr2o3 Lewis Structure Shape

In cr2o3 lewis structure, the central o atom is sp3 hybridized. This is because of the fact that it contains 2 sigma bonds with two cr atoms and remaining hybrid orbital contain 2 pairs. According to sp3 hybridization the structure should be tetrahedral but the actual shape is bent / V-shaped.

Cr2o3 Lewis Structure Formal Charges

The formal charge on the central o atom in cr2o3=6-4/2-4=0.

Formal charge on terminal oxygen atom in cr2o3=6-4/2-4=0.

Formal charge on 2 cr atoms in cr2o3=6-6/2-3=0.

Hence formal charge on central o atom in cr2o3 is 0 and also two o terminal atoms, two cr atoms also contain o formal charge. Hence this compound is overall electrically neutral.

Cr2o3 lewis Structure Lone Pairs

The lone pairs mean how many no of unshared electrons present in cr2o3 that does not take part in bonding. This can be calculated by the following way-

Lone pair present on central o atom in cr2o3=6-4=2 lone pairs.

Lone pair present on terminal cr atom in cr2o3=6-6=0 i.e. 0 lone pair of electron.

Lone pair present on terminal o atoms in cr2o3=6-4=2 lone pairs.

In cr2o3 compound these nonbonding electron pair are shown on the above mentioned atoms as electron dots.

Cr2O3 Hybridization

During hybridization means during bond formation central o atom uses sp3 hybrid orbital to form cr2o3 compound. Central o atom has 6 valance electron out of which 2 unpaired electrons is used for the formation of 2 sigma bonds with two cr atoms. Two cr atoms has 6 valance electron out of which 2 are used in bonding with 2 terminal o atoms.

2 terminal o atoms forms 1 sigma and 1 pi bonds with cr atoms by using its 2 unpaired electrons and remaining 4 electrons which does not take part in bonding with cr atoms present as lone pair of electron. Hence in cr2o3, central o atom uses sp3 hybrid orbital to form cr2o3 compound. according to sp3 hybridization its structure is pyramidal not tetrahedral due to presence of 2 lone pairs.

Cr2O3 solubility

Cr2o3 is insoluble in water, ethanol and even in acetone and also acids. By considering the fact mentioned above it is concluded that cr2o3 is a nonpolar compound. As it is nonpolar in nature, it is soluble in nonpolar solvents like carbon tetrachloride, carbon disulphide etc.

Cr2O3 valance electrons

The total no of valance elctron in cr2o3 is equal to the valance electron present in cr and o atoms. Cr contains 6 and O also contains 6 valance electron. The total no of valance electron present in cr2o3 is (6*2)+(6*3)=12+18=30.

Cr2O3 lewis structure angle

In cr2o3 lewis structure, central o atom is bonded with 2 cr atoms with which 2 o atoms are double bonded with cr atoms in a tetrahedral manner. The central O atom is sp3 hybridized in cr2o3 and also contain 2 lone pairs. As the structure is pyramidal, the angle should be 104.50.

Cr2o3 lewis Structure Resonance

In cr2o3 lewis structure when electron pair movement i.e resonance takes place, 3 resonating structure is obtained. In cr2o3, lone pair of electron present on central o atom is delocalized with the cr=o bonds i.e. with vacant ∏* orbital of cr=o bonds.

Cr2o3 lewis structure Octet Rule

The lewis structure of cr2o3 shows that all the atoms in cr2o3 fulfill their octet. In cr2o3, the central o atom forms 2 sigma bonds with 2 cr atoms and also contains 2 lone pairs. That is why, central o atom satisfy its octet. Two terminal o atom forms double bond with cr atom and also contain 2 lone pairs.

By this terminal o atoms fulfill their octet. 2 cr atoms forms 2 sigma bond and 1 pi bond with central and terminal o atoms. It also contains 1 lone pair. Hence it contains total of 8 electrons and fulfill its octet. Hence by applying octet rule the compound cr2o3 is a stable compound.

Cr2o3 Polar Or Nonpolar?

Cr2O3 is nonpolar compound. As we seen that it is a nonpolar compound it is insoluble in polar solvents like water. Its lattice energy is higher than hydration energy. To break it into Cr3+ and O2- ions higher energy is required. For this reason, it usually does not break into cr3+ and O2- ions.

Is cr2o3 ionic?

Cr2O3 is ionic compound. When cr2o3 ionizes, 2cr3+ ions and 3o2- ions are produced. As therefore, Cr2O3 is overall a neutral compound because total 6 positive charges is neutralized by total 6 negative charges. As because cr is metallic in nature, it acquires positive charge and o is nonmetallic in nature it acquires negative charge.

Is cr2o3 acidic or basic?

Cr2O3 is amphoteric in nature i.e. it both reacts with acid as well as base. When it reacts with acid it behaves like base and when it reacts with base it behaves like acid. When it reacts with acid, it produces hydrated Cr species which is capable of reacting with bases to produce complex salts.

Is cr2o3 tetrahedral?

In Cr2O3, central O atom is tetrahedral arranged around 2 lone pairs and 2 Cr=O fragments. Hence central O atom in cr2o3 is sp3 hybridized. That is why cr2o3 is tetrahedral in nature.

Is cr2o3 linear?

Cr2O3 is not linear because from structure of cr2o3 we see that 2 Cr atoms and 3 O atoms are arranged in angular manner i.e. in bent manner. Hence Question of linear structure does not arise.

Is cr2o3 symmetrical or asymmetrical?

Cr2O3 is symmetrical in nature. When a sigma or mirror plane passes through the compound it divided the compound into 2 symmetric halves. Actually, the mirror plane passes through the O atom in cr2o3 compound, 2 symmetric halves are obtained i.e. Cr=O part.

Cr2O3 Molar Mass

As cr2o3 contains 2 cr atoms and 3 o atoms in it. The molar mass of cr2o3 is equal to the sum of molar mass of 2 cr atoms and 3 atoms. Hence the molar mass of cr2o3 is 151.9904 gm/mol.

Cr2O3 Oxidation Number

O atom has -2 oxidation states. Hence 3 o atoms provide -6 oxidation states. Cr2o3 is overall a neutral compound. For this reason, -6 charge is neutralized by +6 charge. Hence each cr atom provides +3 oxidation state.

Cr2O3 Charge

Cr2O3 is overall a neutral compound. This is because of the fact that -6 charge of o atom is neutralized by +6 charge of cr atoms. Cr2o3 has overall a neutral compound.

Is Cr2O3 Paramagnetic?

Cr2O3 contains a total of 6 unpaired electrons i.e. each cr atoms provide 3 unpaired electron. Hence this compound is paramagnetic due to presence of unpaired of electrons. In cr2O3, each cr atom provides 3BM spin only magnetic moment.

Is Cr2O3 a Strong Electrolyte?

Cr2O3 contains 6 unpaired electrons. This unpaired free electron is responsible for the creation of electricity by cr2o3. For this reason, cr3o3 behaves as a strong electrolyte.

Conclusion

Keeping the above facts in mind about cr2o3 it is stated that cr2o3 is a neutral nonpolar tetrahedral compound. It reacts with both acid and bases to behave as an amphoteric oxide. In cr2o3 the two cr atoms contain +3 oxidation state and 3 o atoms contain -2 oxidation state each.

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