SO lewis structure: Drawings, Hybridization, Shape, Charges, Pair And Detailed Facts


This article discussed how SO lewis structures are drawn and the other characteristics properties of SO molecule such as hybridization, Shape, polarity, and charges, etc.

SO (sulfur oxide) is found as a dilute and colorless gas in nature and has a linear structure. The sulfur atom is bonded with oxygen via a double bond of around 148.1picometer in length. The molar mass of the given entity is 48.064 g/mol.

Related  terms to lewis structure

Before drawing the SO lewis structure, one should have a clear idea about the following definitions:

What are valence electrons?

Those electrons represented in the outermost shell of the atom can only participate in bonding. For instance, sulfur has an atomic number of 16 and has an electronic configuration of 1s2 2s2 2p6 3s2 3p4, and only electrons present in the outermost shell ie, 6 are called valence electrons. Likewise, oxygen belonging to the second period has an electronic arrangement of 1s2 2s2 2pand offers 6 electrons for the bonding.

What do you mean by lone pairs in SO lewis structure ?

The non-bonding electrons are those which do not contribute to chemical reactions/ bonding and are called lone pairs or nonbonding electrons. In the case of SO, sulfur has 4 nonbonding electrons and oxygen has 6.

SO lewis structure octet rule

The role of the octet rule in the chemistry world is quite important as this rule is the answer to every reaction occurring in this universe. In simple words, this rule states that any atom participates in any chemical reaction to attain stability. The concept of the octet rule and lewis structure are inseparable from each other.

According to the statement of the rule ” atoms combine either by transfer of valence electrons from one atom to another atom or by sharing of valence electrons in order to have octet in their valence shells. This is called the octet rule. As shown in the above picture, both sulfur and oxygen have 6 electrons in their outer shell and they both tend to combine so that they can achieve the aim of the full octet.

SO lewis dots

How to draw lewis structure for SO?

Firstly calculate the total no of valence electrons. For example, there are 6 valence electrons in the outermost shell of both the atoms of SO. Hence, there are 12 valence electrons in total.

       Valence electron of sulfur atom = 6

       Valence electron of oxygen atom = 6

 Total valence electrons in SO molecule =12

Calculate the total number of electron pair

Electron pair = total valence electron divided by 2

ie 12/2 =  6  

Position of the central atom, in general, the least electropositive atom occupies the central position. Therefore, since sulphur is less electronegative than oxygen so it will take a central position.

Lewis structures are considered stable only when the given structure is following the octet rule. In other words, the octet of both participating atoms must be completed.

After the distribution of shared pairs of electrons for single bonds, the left electron pairs are used either for multiple bonds or they also consider as lone pairs. Now, by using the above-mentioned rule, we get the lewis structure of SO as shown below:

SO lewis Structure
SO  Lewis structure

Calculation of SO lewis structure formal charges

Generally, the formal charge refers to the total charge carried by an atom. However, in the case of polyatomic atoms,  it involves sharing of electrons as a result the total charge on the molecule is also altered. Therefore,  the formal charge tells about the final charges on the given molecule.

Let’s find out the formal charge on SO using the above equation

General Formula for finding formal charge on SO lewis structure

Total number of valence electrons S = 6

Total number of valence electrons O = 6

Total  valence electrons present in the  SO  = 12/2 = 6

Total number of lone pairs on sulfur =  2 ( ie containing total 4 non bonding electron)

Total number of lone pair on oxygen = 3 ( total 6 non bonding electrons)

Formal charge on  Sulfur = 6 – 4 – ½ (2) = +1

Formal charge on oxygen = 6- 6 – ½ = -1

Hence total charge on the molecule is zero

SO hybridization

SO molecule has triplet ground state as same as in O2 and S2 containing two unpaired electrons with a bond length of 148.1 pm. With the exposure to the infrared light, electrons got excited and the triplet state converted into a singlet state with all paired electrons. Also, the excited state is found to be more reactive than the triplet ground state.

Is SO polar or non-polar?

According to the principle of polarity in chemistry, a molecule can be called polar only if there is a huge difference between the electronegativity of its constituent atoms. As in the case of SO, Sulfur has a value of around 2.58 whereas oxygen has a value of 3.44. Since there is a huge difference between their electronegative values, this molecule comes under the polar category and a dipole is formed between electropositive sulfur and electronegative oxygen.

Since it is a polar molecule, it can be soluble in polar solvents like H2O, CH3OH and DMSO (dimethyl sulfoxide)

Interesting facts about SO

  • Occurrence: It rarely occurs in nature and is usually found in the upper layers of the atmosphere.
  • Production: synthetically, SO is prepared from ethylene episulfoxide. The reaction is given below :

                            C2H4SO ‑‑‑‑‑‑‑‑‑‑‑> C2H4    +   SO

  • Dangerous:  yes, SO is dangerous, and its exposure to the human body causes irritation to the eyes and also leads to breathing problems. Due to instability, this gas is quite flammable and can undergo dimerization to produce another dangerous gas, SO2 (sulfur dioxide) which is relatively more poisonous.
  • Global warming: This gas is also a contributor to greenhouse gases and hence plays a role in global warming
  • Astrochemistry: Sulphur monoxide has been found in the atmosphere of many planets such as Venus and Jupiter
  • Biological activity: sulfur monoxide is also found in the coronary artery of pigs.
  • Production of SO2: So is the main precursor for the synthesis of SO2 which is further needed for the production of many acids such as sulfuric acid and is also used for food preservation.

Additional information:

The other information regarding sulfur monoxide can be found here only.

Also, please click to know about SBr6 Lewis Structure and SBr4 Lewis Structure.

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