Is CBr4 a polar or nonpolar substance?

Carbon tetrabromide, sometimes known as CBr4, is a chemical compound with the formula CBr4. Tetrabromomethane is its IUPAC systematic name. It can be used as a solvent for a variety of different chemical substances. Many pupils may be confused about whether Cbr4 is polar or not. In this essay, I’ll respond to this question and explain its qualities and applications.

Is CBr4 polar or nonpolar, then? Because of the symmetrical arrangement of four bromine atoms around carbon, CBr4 (Carbon tetrabromide) is nonpolar in nature. As a result, the C-Br bond’s dipoles cancel each other out, making CBr4 a nonpolar molecule.

When it comes to the chemical makeup of carbon tetrabromide, there are four bromine atoms and one carbon atom bonded to each other by covalent bonds.

The C-Br bond has a bond energy of roughly 235 kJ.mol1. The compound exists in two polymorphs: crystalline I, which occurs at temperatures higher than 46.9 °C, and crystalline II, which occurs at temperatures lower than 46.9 °C.

Carbon tetrabromide’s molecular mass is determined as follows:

CBr4 mol mass = 1 12 (mol mass of C) + 4 * 79.904 (mol mass of Br) = 331.627 gmol1.

Carbon has an electronegativity of 2.55, while bromine has an electronegativity of 2.96. Because bromine is more electronegative, it attracts the bound electron pair a little more.

The bromine atom obtains a partial negative charge, while the carbon atom gains a partial positive charge.

The polarity in the C-Br bond is generated by the difference in electronegative between carbon and bromine.

Furthermore, the C-Br bond’s polarity assures that the dipole moment is not zero.

When we look at the geometrical structure of CBr4, we can see that all of the C-Br bonds have four dipoles pointing in the opposite direction.

Carbon tetrabromide’s molecular geometry is symmetric in nature, i.e. Tetrahedron.

Because of this symmetry, all of the dipoles cancel each other out, resulting in the molecule’s overall zero dipole moment.

The dipole moment of nonpolar molecules is always equal to zero.

It’s vital to remember that a polar link can exist within a nonpolar molecule. The polarity of such links, however, is cancelled by each other due to the symmetrical geometry.

What Is the Difference Between Polar and Nonpolar Molecules?

Interatomic forces in different sorts of bonding, such as ionic, covalent, metallic, and hydrogen bonds, differ between molecules.

Among all of these bond forces, covalent and ionic are the most powerful.

Depending on parameters such as electronegativity, geometrical shape, and dipole moment, covalent bonds can be polar or nonpolar.

Polar Molecules: Polar molecules are those that have a non-zero dipole moment. The atoms in these compounds have an uneven charge distribution.

When the electronegativity of two covalently connected atoms differs, they form a polar bond.

It signifies that the bound pair of electrons are held differently by both atoms. The linked electrons are drawn somewhat further towards the more electronegative atom, giving it a partial negative charge.

The lesser electronegative atom, on the other hand, obtains a partial positive charge. Two opposed poles form in a polar molecule in this way.

Methanol and H2O are two examples of such molecules. You can look into the explanation for methanol’s polarity.

Nonpolar Molecules: Nonpolar molecules have a dipole moment of zero. The atoms in these compounds have a homogeneous charge distribution.

If both atoms have the same electronegativity, or the same charge distribution on both atoms, the bond formed between them is said to be nonpolar.

It indicates that bound electrons are affected in the same way by both atoms. Both atoms have the same amount of attraction for the linked electrons and have the same charge.

CCl4, Br2, and other similar compounds are examples. You can look into the reason for CCl4’s non-polarity.

CBr4 is a nonpolar molecule for a reason.

The geometrical structure of the chemical compound carbon tetrabromide is a tetrahedron. CBr4 has one carbon atom and four bromine atoms in its molecule.

The central element, carbon, is surrounded by four bromine atoms, resulting in a tetrahedron-shaped structure.

The polarity of the C-Br bond is ensured by the difference in electronegativity between carbon(2.55) and bromine(2.96).

As a result, it guarantees a certain value of dipole moment in C-Br.

The dipole moment is a measurement of a molecule’s polarity.

The dipoles of all C-Br bonds cancel each other in the case of CBr4, because the geometrical shape of CBr4 is symmetrical.

The polarity of a molecule is determined in large part by its geometrical shape.

Carbon tetrabromide is a nonpolar compound due to these properties.

For additional information, watch the video above.

Factors that influence a molecule’s polarity

Electronegativity: The ability of an atom to attract a bound pair of electrons is measured by its electronegativity.

The higher an atom’s electronegativity, the more it attracts bound electrons to its side, giving it a partial negative charge.

Because of unequal sharing of bound electrons, when the electronegativity of two atoms differs, the polarity of both increases.

As a result, a molecule’s polarity is proportional to the difference in electronegativity of the atoms making the connection.

Dipole Moment: The dipole moment is a measurement of a molecule’s polarity. A molecule’s polarity is proportional to its dipole moment.

Compounds with a dipole moment of zero, such as CBr4, are nonpolar in nature.

The dipole moment of a molecule is calculated as the product of charge and distance between them.

Q * R = D

Geometrical Structure: A molecule’s form is an essential aspect in determining its polarity.

Symmetrical structure molecules have a dipole moment of zero, making them nonpolar.

If a nonpolar molecule has any polar bonds, the polarity of those bonds is cancelled by the polarity of those bonds.

The CBr4 Geometrical Shape

Carbon tetrabromide has four bromine atoms and one carbon atom in its molecule. Because the four bromine atoms surround the centre carbon, the molecule takes on a tetrahedral structure.

Bromine has 7 valence electrons and requires 1 electron to be stable. Carbon has 4 valence electrons in its outermost shell.

According to VSEPR theory, the four C-Br bonds form, leaving no lone pairs remained.

CBr4 has a bond angle of roughly 109.5 degrees.

The geometrical structure of the carbon tetrabromide molecule is shown above.

CBr4’s Characteristics

Carbon tetrabromide appears as a colourless crystal.

It has a particular fragrance about it.

CBr4 has a density of 3.42 g/cm3 in the solid state.

This substance is water insoluble.

Carbon tetrabromide has a molecular mass of 331.63 g/mol.

This compound has a boiling temperature of 189.5 °C and a melting point of 91.0 °C.

It has a vapour pressure of 5.33 kPa at a temperature of roughly 96.3 °C.

CBr4’s Applications

In several chemical reactions, it is commonly used as a sedative.

It is also employed as a grease, oil, and wax solvent.

It is utilised as a polymerizing agent in the polymer industry.

It has a lot of potential in the agrochemical industry.

Because of its great density, it is utilised to separate different minerals.

Conclusion

Four bromine atoms are joined by covalent connections in the molecule carbon tetrabromide. The polarity of the C-Br bond rises due to the difference in electronegativity of carbon and bromine.

However, owing of the symmetric geometric structure of Carbon tetrabromide, the compound is nonpolar, as the polarity of the C-Br bonds cancels out, resulting in the nonpolar CBr4 molecule.

So, if you have any queries about CBr4’s polarity, feel free to post them in the comments area. We’ll get back to you as soon as we can.

Read more: Hybridization, Polarity, and the MO Diagram in the I3 Lewis Structure

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.

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