CBr4 is a covalent (nonpolar covalent) compound because when one nonmetal combines with another nonmetal, it usually forms a covalent compound. Here, C is a nonmetal and Br is also a nonmetal. So when they combine, it forms a covalent compound.
Well, now you have got to know that CBr4 is a covalent compound, but let me explain the in-depth reason why CBr4 is a covalent compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is CBr4 a Covalent compound?
As mentioned above, you can simply remember that when the nonmetal combines with another nonmetal, the bond between them is a covalent bond.
Here in CBr4, the C atom is a nonmetal and the Br atom is also a nonmetal.
Hence the bond between them is a covalent bond.
How does the covalent bond form in CBr4?
In CBr4, there are two atoms;
C and Br.
About Carbon (C):
Carbon atom have 6 electrons.
The electrons arrangement in Carbon (C) is 2, 4.
So the outermost orbit of Carbon atom has 4 electrons.
Now in order to achieve a stable octet, the Carbon atom needs 4 more electrons.
Hence during the chemical reaction, the Carbon atom will gain 4 electrons from the combining atom to form a stable octet.
About Bromine (Br):
Bromine atom have 35 electrons.
The electrons arrangement in Bromine (Br) is 2, 8, 18, 7.
So the outermost orbit of Bromine atom has 7 electrons.
Now in order to achieve a stable octet, the Bromine atom needs 1 more electron.
Hence during the chemical reaction, the Bromine atom will gain 1 electron from the combining atom to form a stable octet.
What happens when C and Br combine?
When C and Br combine with each other, the Carbon atom and Bromine atoms mutually share their 1-1 electrons with each other.
Because of this the carbon atom will have 8 electrons in its outermost orbit and similarly the bromine atoms will also have 8 electrons in its outermost orbit.
As a result, the carbon atom and bromine atoms will have a stable octet.
And finally, as the bond formed between the carbon and bromine is due to the mutual sharing of electrons, it is considered a covalent bond.
Thus, CBr4 is a covalent compound.
Is CBr4 polar covalent or nonpolar covalent?
In order to know whether CBr4 is a polar covalent molecule or nonpolar covalent molecule, we have to check the electronegativity difference of the combining atoms.
If the electronegativity difference (ΔEN) is less than 0.4, then the bond is nonpolar covalent bond.
Now the electronegativity of Carbon and Bromine are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).
- Electronegativity of Carbon (C) = 2.55
- Electronegativity of Bromine (Br) = 2.96
So for CBr4, the electronegativity difference (ΔEN) = 2.96 – 2.55 = 0.41
This value lies between 0.4 to 1.7, which indicates that the bond between Carbon (C) and Bromine (Br) is polar covalent bond.
But if you look at the 3D structure of CBr4, you can see that the structure of CBr4 is symmetrical.
As both the bonds (C-Br) are symmetrical and the CBr4 molecule has a symmetrical geometry, their bond polarity gets canceled with each other.
Hence, CBr4 is a nonpolar covalent molecule.
I hope you have understood the reason why CBr4 is a nonpolar covalent compound.
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online chemistry learning platform that provides students with easily understandable explanations.
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