Brcl lewis structure, Characteristics: 13 Must To Know Facts


BrCl is a strong oxidizing agent mainly used for analytical chemistry purpose.

Bromine Chloride is highly reactive species, in fact it decomposes at room temperature. We can explain the properties of it with the help of the BrCl lewis structure.

How to draw Brcl lewis structure?

With using the atomic symbols of Chlorine and Bromine, the BrCl lewis structure shows the distribution of the outer orbit electrons, spread around the particular atom in the molecule. To draw the structure some steps are followed;

Count the valence electrons of the molecule:

In modern Periodic table the halogen atoms both Chlorine and Bromine are in group 17. The outer shell electronic distribution of Chlorine atom is [Ne] 2s2 2p5. Bromine atom contains its outer orbit electrons in 4s and 4p with the arrangement: [Ar] 3d10 4s2 4p5.

Hence Chlorine and Bromine jointly have fourteen loosely bounded electrons means seven pairs of electrons for molecule formation.

Skeletal formation of the BrCl lewis structure:

BrCl is a diatomic molecule, so here no need to choose the central atom as for polyatomic molecule. The atomic symbols of the halogen atoms written sidewise, for Chlorine ‘Cl’ and Bromine ‘Br’ and the valence electrons are arranged accordingly.

Cover the Octet rule:

To form energetically stable molecule, both the halogen atoms must have to cover the last orbit with eight electrons, so they share electrons cloud. Hence a single bond (sigma bond) forms, that is drawn by a single line in BrCl lewis structure.

Calculate the formal charge of the individual atom:

After making a lewis structure we have to calculate the formal charge of the halogen atoms. If both Chlorine and Bromine have zero formal charge over them, then only the BrCl lewis structure will be a stable one.

Brcl lewis structure resonance

When an atom has unshared electrons in a molecule, these can be able to spread into vacant orbital of neighbor atom of the molecule and we get canonical resonate structure, which are stabilized by conjugation energy.

Both electronegative halogen atoms form the BrCl lewis structure through the sigma bond formation. If the electron cloud delocalizes there will be electronic repulsion which destabilize the structure. So we get no resonate structure.

Brcl lewis structure shape

BrCl lewis structure shape is slightly different from the geometry which becomes clear from the orbital electronic arrangement. For the bulkiness of the lone pair, it distorted the geometry, which is called the shape of the molecule.

As AXE3 type molecule (where A is Br, X is Cl and E represent the lone pair) the geometry of the molecule should be tetrahedral but both of the halogen atoms contain unshared negative charged cloud. For the equal repulsion we get a linear shaped molecule.

brcl lewis structure
BrCl lewis structure shape

Brcl lewis structure formal charge

Considering the bonding electron cloud is equally distributed, formal charge can be calculated by the equation, f = (n – lp – (bp/2)), where ‘n’ is outer shell electrons, lp is nonbonding electrons and bp is electron cloud distributed for bond formation.

From the Periodic table, we know that halogen atoms, here both Chlorine and Bromine have seven electrons in their last filled electronic shell. In the BrCl lewis structure, after the bond formation each halogen atom has three pairs of electrons which remain as unshared electrons.

Hence for both Chlorine and Bromine atom, formal charge in above BrCl electron dot structure is, {7- 6 – (1/2×2)} = 0.

As the atoms of this above electron dot structure have “zero” (0) formal charge, hence this skeletal of BrCl lewis structure is very much energetically stable compared to the other possible electron dot structure.

Brcl lewis structure angle

Bond angle is measured as the average angle between the adjacent covalent bonding orbital which changes with different configurations of electron dot structure.

Being a diatomic molecule, the two atom’s 3p and 4p orbital respectively are overlapped directly, results a sigma bond formation with sharing the electron cloud. Hence in 3D space they belong to a plane, where the angle between them can only be 180 degree.

brcl lewis structure
BrCl lewis structure bond angle

Brcl lewis structure octet rule

In main group elements, eight electrons are arranged in their valence orbit, which describes electron’s wavy nature, in such a way that the molecule becomes inactive and become stabilized which is termed as Octet rule.

In the BrCl lewis structure both Bromine (Br) and Chlorine (Cl) each have loosely bounded seven negative particles in their outer energy shell. By sharing the electron cloud they easily cover up the outer orbit and become energetically stable like inert gas.

Brcl lewis structure lone pairs

Electron cloud that are loosely bounded by nuclear force, participate to reaction for bond formation but some remain unshared during the overlapping. These electron cloud are called lone pairs with higher electronic density.

To satisfy the Octet rule for stabilization, the two atoms in BrCl lewis structure need one electron each. Hence among the participated outer filled loose electrons one pair is utilized in bonding and remaining six pairs of electrons concentrate over their parent atom.

Brcl valence electrons

The outer shell electrons which are loosely bounded by nuclear force of attraction due to the shielding effect of the inner shell electrons, called valence electrons. They can absorb energy to be in excited state to participate in chemical reactions.

In BrCl lewis structure the two halogen atoms contain fourteen electrons, where Bromine atom has seven negatively charged particles in the 4p orbital whereas the Chlorine atom has seven electrons in the “p” orbital of 3rd orbit.

The core orbital electrons of the halogen atoms are tightly bounded to their nucleus by strong nuclear force, but with increasing the number of orbits (electronic energy level) from the nucleus, these force lowers.

For this reason the outer shell 3p and 4p electrons of Chlorine and Bromine atoms are loosely tied up. They act as free energy particle and can move to form bond between the atoms.

Brcl hybridization

Hybridization is the concept in Valence Bond Theory, for covalent compounds where atomic orbitals intermixes to form energetically equivalent orbital, so that it become easy for overlapping during molecular orbital formation.

To form Brcl lewis structure sigma bond the energetically comparable ‘p’ orbitals directly overlapped, where only one electron is needed per atom and they have vacant space. Hence no requirement for hybrid orbital formation.  

Brcl solubility

BrCl solubility in any solvent is measured by the concentration which can be dissolved until the equilibrium occurs in the solution. This depends on facts like the type of bonding between the inter-halogen compound, polarity, temperature etc.

Having the electro-negativity difference, polarity exists in the molecule results salvation in polar solvent water with the amount of 8.5 g/L. It is also soluble in Carbon disulfide (CS2) and ether type solvents.

Is Brcl ionic?

If atoms of a molecule are bonded together by electrostatic force, with completely electronic transformation, then it is ionic compound, can be shown between metal and nonmetal elements. In spite this if electron cloud is shared between atoms, is called covalent compound.

Bromine and Chlorine both are non metal elements, are joined together by sharing electron cloud of their outer most orbital 4p and 3p respectively. So the electron cloud of the bond is not concentrate only over particular atom. It is a covalent molecule, not ionic.

Being a covalent molecule we can see the melt point and boiling point of the BrCl lewis structure is very less, (-54 ̊ C) and 5 ̊ C respectively where these properties of an ionic molecule is very high as the opposite charges are bound by strong electrostatic force.

Is Brcl acidic or basic?

BrCl is a very reactive inorganic species, which decomposes even at room temperature.

Its solubility in water is good (8.5 g/L) which produces hypobromous acid. So the water solution of BrCl is acidic in nature.

Is Brcl polar or nonpolar?

In the BrCl lewis structure, electro-negativity of Chlorine (Cl) is 3.16 and that of Bromine is 2.96 on the basis of Pauling scale, so difference creates charge separation in bond and which leads the molecule to be polar.

In the molecule both the atoms are electron-egative in nature as they belong to the group no 17 ( right column of the Periodic table), but for having ‘d’ orbital the outer orbit electrons of Bromine are more diffused, hence Chlorine has more tendency to pull the bonding electron cloud.

BrCl lewis structure is linear, so the vector direction of electro-negativity towards the Chlorine atom can’t be cancel out which results of dipole moment as it is measured by the multiplication of the charge separation (δ) and the distance between the charges (r) and BrCl become polar.

brcl lewis structure
BrCl lewis structure polarity

Conclusion

The diatomic inter-halogen compound BrCl is unstable at room temperature, and the other properties are easily explained by the electron dot configuration.

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