CHBr3 Lewis Structure, Characteristics: 13 Must To Know Facts


CHBr3 is the chemical formula of bromoform. It is also known as tri- brormo methane.

Brormoform or tribormomethane (CHBr3) is the chemical compound consists of three elements i.e. one carbon, one hydrogen and three bromine atoms. It is a liquid compound with no colour and has smell like chloroform. Bromoform is a quite toxic compound to inhale, skin absorption and also to ingest.

How to draw CHBr3 lewis structure?

There are some steps to draw the lewis structure of any molecule. Following are the some steps to draw lewis structure.

  • Count valence electrons of each atom
  • Select the central metal atom which is least electronegative in nature
  • Make the bonding within central atom and outer atoms
  • Remaining valence electrons after bonding place on outer atoms to complete octet
  • Lone electron pair count
  • Count the formal charges on each atom present

In CHBr3 lewis structure, it has only three elements one carbon, one hydrogen and three bromine atoms. In this structure C atom has electronegativity 2.55, H atom has electronegativity 2.20 and bromine atom has electronegativity 2.96. H atom has lowest electronegativity but it cannot place centrally as it has not sufficient electrons for bonding in its valence shell.

If we compare C and Br atom, C is least electronegative than Br atom thus it occupies central position. Then calculate its valence electrons. All the three bromine atoms and one hydrogen atom attached to central C atom with single covalent bonds. There are total four covalent bonds formed between one Carbon and hydrogen (C-H) and carbon and three bromine (C-Br) atoms.

CHBr3 lewis structure

CHBr3 valence electrons

Carbon atom comes under 4th periodic table group, Bromine atom comes under 17th periodic table group and hydrogen atom comes under 1st periodic table group. Thus carbon atom has four valence electrons, hydrogen atom has one valence electron and bromine atom has seven valence electrons in their outer valence shell orbitals. So, the total valence electrons in CHBr3 lewis structure are:

Carbon atoms valence electrons = 04

Hydrogen atoms valence electrons = 01

Bromine atoms valence electrons = 07

Total valence electrons in CHBr3 lewis structure = 04 (C) + 01 (H) + 07 x 03 (Br) = 26

Hence, there are total twenty six valence electrons are present in CHBr3 lewis structure.

If we count the total electron pairs, we have to divide total valence shell electrons by two.

Therefore total electron pairs in CHBr3 lewis structure = 26 / 2 = 13

Hence, thirteen total electron pairs are present on CHBr3 lewis structure.

Valence electrons on CHBr3 lewis structure

CHBr3 lewis structure octet rule

Octet means eight electrons. Octet rule is the eight electrons should present on valence shell orbital on any atom to be known as complete octet. In CHBr3 lewis structure, there are total 26 valence electrons are present, out of which eight electrons are involved in bonding within central C atom and outer H and Br atoms. So, there are four bond pair electrons are present which forms single covalent bonds between one C-H and three C-Br.

The remaining 18 valence electrons should distribute within all outer atoms to complete its octet. Hydrogen atom cannot place more than two electrons in its valence shell outer orbital as it belongs to 1st group of periodic table. Thus hydrogen atom already has two (C-H) bond electrons pairs present on it, so we cannot put more electrons on H atom. Hence remaining 18 valence electrons should put on only three Br atoms.

Hence, each bromine atom can take more six valence electrons on it. So, all the eighteen valence electrons get occupied on three Br atoms and we are now no left with more valence electrons for more distribution. Now, each bromine atom has total eight electrons and also carbon atom has eight electrons, so they have complete octets rather hydrogen atom has only two electrons accord to its capacity.

CHBr3 lewis structure showing complete octet of C and three Br atoms

CHBr3 lewis structure lone pairs

As there are 26 valence electrons present on CHBr3 lewis structure, from them 8 valence electrons are engaged in bonding and being four bond pairs. Therefore, there are 18 valence electrons left for further distribution on outer atoms.  Hydrogen atom already fulfil its capacity of electrons as it already has two electrons as a bond pair present on it, so there is no need to add more electrons on hydrogen atom.

The left over 18 electrons are then placed on three bromine atoms of CHBr3 lewis structure. Hence each Br atom can adopt more six valence electrons, so all those 18 valence electrons get placed on three bromine atoms. Now, each bromine atoms has six non- bonding electrons. Means each bromine atom has three lone electron pairs present on it. Therefore, three bromine atoms has total nine lone electron pairs. Thus, CHBr3 lewis structure has total three lone electron pairs.

Total nine lone pair electrons present on CHBr3 lewis structure

CHBr3 lewis structure formal charge

Formal charge can be calculated by applying a formula given as follows:

Formal charge = (valence electrons – non-bonding electrons – ½ bonding electrons)

To calculate the formal charge of CHBr3 lewis structure we have to calculate the formal charge of each atoms present on it i.e. C, H and Br atoms as shown as below:

Carbon atom: Valence electrons on Carbon atom = 04

                       Non- bonding electrons on Carbon atom = 00

                       Bonding electrons on Carbon atom = 08 (2 electrons in single bond)

Carbon atom has Formal charge is = (04 – 00 – 08/2) = 0

So, the carbon atom present in CHBr3 lewis structure has zero formal charge.

Bromine atom: Bromine atom have Valence electrons = 07

                         Bromine atom have Non- bonding electrons = 06

                            Bromine atom have Bonding electrons = 02 (2 electrons in single bond)

Bromine atom has Formal charge is = (7 – 6 – 2/2) = 0

So, the bromine atom of CHBr3 lewis structure has zero formal charge.

Hydrogen atom: Valence electrons on Hydrogen atom = 01

                          Non- bonding electrons on Hydrogen atom = 00

                             Bonding electrons on Hydrogen atom = 2 (single bond = 2 electrons)

Hydrogen atom has Formal charge is = (01 – 00 – 2/2) = 0

So, the hydrogen atom present on CHBr3 lewis structure has zero formal charge.

Hence, the entire C, H and Br atoms of CHBr3 lewis structure has zero formal charge present on it.

CHBr3 lewis structure resonance

The presence of multiple bonds means double and triple bonds in any lewis structure with the presence of lone electron pairs and the formal charge present on it is the characteristics to draw the resonance structure of any lewis structure or any chemical compound. If any chemical compound fulfil all these conditions then it is easy to draw lewis structure of any molecule.

In CHBr3 lewis structure, there is no such condition is present to draw the resonance structure. As there is only single covalent bonds are present all over the CHBr3 molecule i.e. C-H and C-Br single covalent bonds. Also rather than this there is no formal charge is present. But it has nine lone pair electrons present on CHBr3 molecule. Due to this the resonance structure of CHBr3 lewis structure is not possible.

CHBr3 lewis structure shape

VSEPR theory said that, if the molecule consists of central atom joined with outer four bonding atoms. Then it follows the AX4 generic formula of VSEPR theory. Where, A is a central atom and X is outer bonded atom. AX4 generic formula consisting molecules have tetrahedral molecular geometry and shape.

The CHBr3 lewis structure molecule follows AX4 generic formula as per the VSEPR theory. In CHBr3 molecule, the central carbon atom gets linked or joined with four outer bonding atoms i.e. one hydrogen atom and three bromine atoms. Hence the CHBr3 lewis structure or molecule has tetrahedral molecular geometry and shape.

CHBr3 hybridization

The CHBr3 lewis structure has followed the AX4 generic formula of VSEPR theory. So, it has tetrahedral molecular geometry and shape as the central carbon atom get attached to four outer atoms i.e. one hydrogen and three bromine atoms. Thus, the central carbon atom of CHBr3 molecule has sp3 hybridization. Hence, CHBr3 lewis structure is sp3 hybridized.

CHBr3 lewis structure angle

As the CHBr3 lewis structure is following AX4 generic formula of VSEPR theory, as the central carbon atom of CHBr3 molecule is attached to four atoms like three bromine atoms and one hydrogen atom. Thus it has tetrahedral molecular geometry and tetrahedral shape. Also it has sp3 hybridization as per the VSEPR theory AX4 generic formula.

So, CHBr3 lewis structure has 109.5 degree bond angle within hydrogen carbon bromine (H-C-Br) bond and bromine carbon bromine (Br-C-Br) bond. Hence, CHBr3 lewis structure has 109.5 degree bond angle within its all atoms present in it.

CHBr3 solubility

Bromoform (CHBr3) is soluble in the following solution or solvents:

  • Water
  • Chloroform
  • Benzene
  • Petroleum ethers
  • Oils
  • Ethanol
  • Ligroin
  • Acetone
  • Naptha solvent
  • Volatile oils

Is CHBr3 ionic?

No, Bromoform CHBr3 molecule is not ionic but it is covalent molecule.

Why CHBr3 is not ionic?

In CHBr3 lewis structure, the central carbon atom gets linked with four outer elements i.e. one hydrogen and three bromine atoms. The bond between each carbon hydrogen (C-H) and carbon bromine (C-Br) atoms are single covalent bond which is a strong bond. Thus CHBr3 molecule is covalent and not ionic in nature.

How CHBr3 is not ionic?

CHBr3 molecule is not ionic because it has covalent bonds within each carbon hydrogen and bromine atoms bonding, which is a very strong bond and cannot form ions within the molecule. As the covalent bond is not a weak bond to breaks easily to form ions. Thus, the CHBr3 molecule is being covalent molecule rather than ionic.

Is CHBr3 acidic or basic?

Yes, CHBr3 molecule is acidic in nature and bot basic, as it reacts with basic molecules to donated or liberate protons. Thus acids are the substances which can liberate or donate protons to other bases or chemical compounds.

Why CHBr3 is acidic?

CHBr3 molecule is acidic in nature because when it dissolve in water it can easily liberate or donate or give H+ ions i.e. protons when reacts with water. Thus, it is acidic in nature.

How CHBr3 is acidic?

Acids are the chemical compounds which has pH value less than 7 and this compounds are determined my easily donation or liberation of its protons or H+ ions to water or any other basic solution. The CHBr3 molecule is also produces H+ ions or donates it protons when dissolve in water or reacts with other basic solutions. Thus it is acidic in nature.

Is CHBr3 polar or nonpolar?

Bromoform (CHBr3) molecule is polar molecule in nature.

Why CHBr3 is polar?

Any molecule or chemical compounds have the partition of electric charges i.e. they create dipole moments or having multiple moments, that are polarity of molecule or the molecule is being polar. CHBr3 molecule has polar bonds because of the electronegativity difference between C, H and Br atoms present in it. Thus CHBr3 is a polar molecule in nature.

How CHBr3 is polar?

The CHBr3 molecule has a symmetrical arrangement of atoms or elements present in it and being polar in nature. As the central carbon atom of CHBr3 molecule is attached with four atoms like one hydrogen atom and three bromine atoms, thus it has a tetrahedral molecular geometry and shape. Also it does not have any lone electron pair on central carbon atom. Due to its symmetrical arrangement CHBr3 molecule is being polar.

Is CHBr3 tetrahedral?

Yes, CHBr3 molecule or lewis structure has tetrahedral shape as per the VSEPR theory molecular geometry.

Why CHBr3 is tetrahedral?

The central C atom of CHBr3 molecule is attached with four outer bonding atoms like H and 3Br atoms, so it has tetrahedral geometry.

How CHBr3 is tetrahedral?

The CHBr3 molecule follows AX4 generic formula of VSEPR theory which says the molecule with central atom having no lone electron pair but bonded with four outer atoms has tetrahedral geometry, thus CHBr3 is tretrahedral.

Is CHBr3 linear?

No, CHBr3 is not linear, because it is a tetrahedral molecule.

Why CHBr3 is not linear?

CHBr3 bromoform molecule has tetrahedral geometry and shape thus it is not linear.

How CHBr3 is not linear?

CHBr3 molecule has VSEPR theory’s AX4 generic formula according to which it has tetrahedral geometry or shape. Thus CHBr3 is not linear molecule.

Conclusion:

In CHBr3 lewis structure, there are total 26 valence electrons, out of which eight bonding electrons and 18 non- bonding electrons. It has total nine lone electron pairs. There is zero formal charge present on CHBr3 molecule. It has tetrahedral geometry and shape. CHBr3 has sp3 hybridization with 109.5 degree bond angle. It is covalent molecule with acidic nature and also has polar nature.

Dr. Shruti Ramteke

Hello everyone I am Dr. Shruti M Ramteke, i did my Ph.D in chemistry. I have five years of teaching experience for 11-12 standard, B,Sc and MSc in chemistry subject. I have published total five research articles during Ph.D on my research work and i have fellowship from UGC for my Ph.D. My Masters with specilization Inorganic chemistry and my graduation with chemistry, zoology and environmental science subjects. thank You

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