CS Lewis Structure, Characteristics: 13 Must To Know Facts


CS is the chemical formula for carbon mono- sulphide. It consists of one carbon and one sulphur atom.

Carbon mono- sulphide has a chemical formula CS which has some synonyms like carbon sulphide and sulphidocarbon. The molecular weight of carbon mono- sulphide (CS) is 44.08. It is an organo sulphur compound. The IUPAC name of carbon mono- sulphide is methanidylidynesulfanium and its molecular formula is CS.

How to draw CS lewis structure?

To draw lewis structure some points to be remember that calculation of valence electrons, most electronegative element should possess central position, bonding within all elements, counting formal charge, apply octet rule on each atom of the structure, calculating lone pair electrons, etc.

In CS lewis structure, there are only two elements are present i.e. carbon atom and sulphur atom making it a diatomic molecule. First we have to check the group positions of S and C atom in the periodic table. So, carbon atom is in 4th periodic table group and sulphur atom is in 16th periodic table group. Thus, the C atom has total 4 valence electrons and S atom has total 6 valence electrons in their outer valence shell orbitals.

In CS lewis structure, there should not be a central atom as it is a diatomic molecule consisting of only two atoms. So, both C and S atoms can put behind each other in the lewis structure, then make bonding between them according to its valence electrons are present on it. Lastly complete the octet of each atom of CS lewis structure after bonding and count lone electron pairs present on CS lewis structure.

cs lewis structure
CS lewis structure

CS valence electrons

CS lewis structure is a diatomic structure consisting of only two elements i.e. carbon atom and sulphur atom. Both C and S atoms are belongs to the 4th and 16th group of periodic table respectively. Thus both C and S atoms have 4 and 6 valence electrons in their outer valence shell orbitals.

Valence electrons on C atom = 04

Valence electrons on S atom = 06

Therefore, total valence electrons on CS molecule is = 4 (C) + 6 (S) = 10

Hence, the CS lewis structure has total ten valence electrons present on it.

Total electron pairs on CS lewis structure – 10 / 2 = 5

CS lewis structure has total five electron pairs.

Out of these ten electrons six electrons are involved in bonding between C and S atom, making a triple (C-S) bonds within carbon and sulphur atom.  So, 10 (valence electrons of CS) – 6 (bonding electrons of CS) = 4 valence electrons remains. Since, six electrons are involved in bonding; we are now left with only 4 valence electrons in CS lewis structure.

CS lewis structure valence electrons

CS lewis structure lone pairs

CS lewis structure has total ten valence electrons present on it. If we make a single bond between C and S atom, then two electrons get engaged in bonding out of 10 electrons. Hence, now we are remain with eight valence electrons for further distribution of electrons in CS lewis structure.

Thus, there is only one lone electron pair present on carbon atom. Also the lone electron pairs present on sulphur atom is three. Therefore, total lone electron pairs on CS lewis structure is 1 (C) + 3 (S) = 4. Hence the CS lewis structure has total four lone electron pairs present on it.

CS lewis structure octet rule

In CS lewis structure, there are 4 valence electrons on C atom and 6 valence electrons on S atom. When bonding form between C and S atoms, first we will make a single bond between C and S atom, so we are remained with more eight valence electrons i.e. four lone pair electrons for further sharing or distribution.

But at this situation the octet of C atom has incomplete as there are only four electrons are present on C (one bond pair and one lone pair) and S atom has total eight electrons (one bond pair and three lone electron pairs) i.e. complete octet. Now, to complete the octet of C atom we have to move lone electron pairs of S atom in centre to form triple bond between C and S atoms.

Thus, now we are getting three bond pair electrons and one lone pair electrons on both C and S atoms respectively. Hence, now the carbon atom has complete octet with eight electrons (one lone pair and three bond pairs). Also the sulphur atom has complete octet with eight electrons (one lone pair and three bond pairs). So, the C and S atoms of CS lewis structure has complete octet.

CS lewis structure showing complete octet of C and S atoms

CS lewis structure formal charge

Formal charge calculation is done with the help of the following formula:

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

While calculating the formal charge for CS lewis structure, we have to calculate the formal charge for single C and single S atom as follows:

Carbon atom: Valence electrons on carbon atom = 04

                       Non- bonding electrons on carbon atom = 02

                       Bonding electrons on carbon atom = 02 (single C-S bond)

Formal charge on carbon atom is = (4 – 2 – 2/2) = +1

So, the carbon atom of CS lewis structure has plus one (+1) formal charge.

Sulphur atom: Sulphur atom have Valence electrons = 06

                        Sulphur atom have non- bonding electrons = 06

                        Sulphur atom have Bonding electrons = 02 (single C-S bond)

Formal charge on sulphur atom is = (6 – 6 – 2/2) = -1

So, the sulphur atom of CS lewis structure has minus one (-1) formal charge.

Formal charge on CS lewis structure

CS lewis structure resonance

In CS lewis structure, there are four resonance structures are possible. In the following first resonance structure the electron density is more on S atom and having single C-S covalent bond with formal charge +1 on C atom and -1 on S atom. In second and third resonance structure, there is a double C=S bond with zero formal charge on C and S atom.

It is a stable form of structures, as there is no formal charge on both C and S atom and having one lone electron pair on c and two lone pair electrons on S atom. In last resonance structure, there is a triple bond present within C and S atoms and both have single lone electron pairs. The C atom has -1 formal charge and S atom has +1 formal charge present on it. All the CS molecule resonance structure is formed by shifting of electrons and minimization of charge present on it.

Resonance structures of CS lewis structure

CS lewis structure shape

CS lewis structure has a linear shape as it is a diatomic molecule and having only two atoms present in it i.e. the carbon atom and sulphur atom, which is joined with each other with a triple bond containing single lone electron pairs on each atom. CS lewis structure has linear molecular geometry and electron geometry.

According to VSEPR theory, the molecule having only two atoms with lone electron pair following the generic formula AXE and it has linear geometry or shape. Thus, the CS lewis structure has AXE generic formula and has linear shape.

CS hybridization

In CS lewis structure, there is a triple bond within C and S atoms, so there is a one sigma bond (σ)  and two pi bonds (π) are present. In hybridization of CS structure, pi bond is not involved because p orbitals are formed by side-to-side overlap and there is an end-to-end overlap of two orbitals in sigma bond (σ).

Also as per the VSEPR theory, the molecule with one bonded atom and one lone electron pair following AXE generic formula having linear shape or geometry and also has sp hybridization. So, the CS lewis structure following AXE formula has linear shape and geometry and also it has sp hybridization.

CS lewis structure angle

The CS lewis structure following VSEPR theory AXE generic formula, where A = central atom, X = bonded atoms and E = lone electron pairs on central atoms. So, it has linear shape and geometry with sp hybridization. Thus the CS lewis structure has 180 degree bond angle with 1.5349 A unit bond length.

CS solubility

Carbon mono- sulphide (CS) is a gaseous compound and insoluble in:

  • Water

Is CS ionic?

No, CS molecule is not ionic rather it is a covalent molecule.

Why CS is not ionic?

In CS lewis structure, both the carbon and sulphur atoms are belongs to 14th and 16th group of periodic table and having 4 and 6 valence electrons respectively. Both C and S atoms comes under non- metallic group in periodic table which forms covalent bonds with each other. So, both C and S atoms are non- metals which are covalent in nature. Thus, CS molecule is a covalent molecule.

How CS is not ionic?

If we see the CS lewis structure, the bond formed between C and S atom is formed by sharing of three electron pairs. Therefore there is a formation of a triple bond within C and S atoms. Triple bond is a covalent bond, so we can say CS molecule is a covalent molecule and not ionic.

Is CS acidic or basic?

CS molecule is not acidic or basic rather it is a neutral molecule.

Why CS is not acidic or basic?

CS molecule resembles to CO molecule and most of the similar properties. CS does not show acidic or basic nature as there is a presence of triple bond between C and S atom and not sufficient lone electron pairs are present for further sharing.

How CS is not acidic or basic?

CS is a neutral molecule and not showing any acidic or basic character due to the insufficient lone electron present on CS molecule. So, further donation or acceptation of electrons is not possible with other compounds. But it can act as a ligand in inorganic compounds to form complex compounds.

Is CS polar or nonpolar?

CS molecule is slightly polar in nature.

Why CS is slightly polar?

In CS molecule, the C and S atoms have nearly same electronegativity difference, i.e. electronegativity of C is 2.55 and electronegativity of S is 2.58. Thus, CS molecule is slightly polar in nature.

How CS is slightly polar?

There is no polar bond is present in CS molecule and also it is a linear structure, so there is a dipole moment which points towards C along the C-S triple bond in CS molecule. Hence, carbon mono- sulphide is being a slightly polar molecule.

Conclusion:

CS is known as carbon mono- sulphide having triple bond between C and S atoms. It has total 10 valence electrons and two lone pair electrons. It is linear in shape with sp hybridization and 180 degree bond angle. Both C and S atoms have complete octets. It is a covalent molecule, neutral and polar in 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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