Simple Procedure for writing Lewis Structures – Lewis Structures for sulfur trioxide (SO3)

Lewis Electron Dot Structure of sulfur trioxide SO₃

A simple procedure for writing Lewis Structures was given in a previous article entitled “Lewis Structures and the Octet Rule”. Several worked examples relevant to this procedure were given in previous posts please see the Sitemap - Table of Contents (Lewis Electron Dot Structures).

Consider the case of sulfur trioxide, SO₃. SO₃ is used for the industrial production of sulfonates - organic compounds with a sulfur carbon bonds - when it reacts with organic compounds. A well known and mass produced sulfonate is sodium dodecylbenzenesulfonate (also commonly referred to as linear alkylbenzene sulfonate or LAS) which is a series of organic compounds with the formula C₁₂H₂₅C₆H₄SO₃Na. It is a colourless salt with useful properties as a surfactant. It is usually produced as a mixture of related sulfonates. LAS is a major component of laundry detergent.

SO₃ plays also a major role in acid rain formation since it is hydrated in the atmosphere to form sulfuric acid and sulfates at an increased reaction rate due to the rather high water content in the troposphere.

The following steps are used to draw the Lewis Structure(s) of SO₃:

Step 1: The central atom will be the S atom since it is the less electronegative. Connect the atoms with single bonds:

Step 2: Calculate the # of electrons in p bonds (multiple bonds) using formula (1) :

Where n in this case is 4 since SO₃ consists of four atoms.

Where V = (6 + 6 + 6 + 6) = 24   Therefore, P = 6n + 2 – V = 6 * 4 + 2 – 24 = 2      So there are 2 p electrons in SO₃ and therefore 1 double bond must be added to the structure of Step 1.

 

Step 3 & 4: One double bond must therefore be placed through the 3 S-O bonds. Therefore, the Lewis structures of SO₃ are as follows:

The above simple procedure for drawing Lewis electron dot structures is also shown in the following video:

 

 

 

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Relevant Posts

Lewis Structures|Octet Rule: A Simple Method to write Lewis Structures

Lewis structure of SO2 – Simple Procedure for drawing Dot structures

Lewis Dot Structure of the sulfite ion SO3-2

 

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References

1. G.N. Lewis, J.A.C.S, 38, 762-785, (1916)
2.  E. C. McGoran, J. Chem. Educ., 68, 19-23 (1991)
3. A.B.P. Lever, J. Chem. Educ., 49, 819-821, (1972)

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Key Terms

resonance structures of sulfur trioxide SO3, Lewis electron structures of SO3, chemical formula of SO3, simple method for drawing Lewis structures of SO3,

 

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Simple Procedure for writing Lewis Structures – Lewis Structures for nitric acid (HNO3)

Lewis Electron Dot Structure of nitric acid HNO₃

A simple procedure for writing Lewis Structures was given in a previous article entitled “Lewis Structures and the Octet Rule”. Several worked examples relevant to this procedure were given in previous posts please see the Sitemap - Table of Contents (Lewis Electron Dot Structures).

Let us consider the case of the Lewis electron dot structure of nitric acid HNO₃ (HNO₃ Lewis structure).

Nitric acid is a strong oxidizing agent and it dissolves practically all metals except gold and platinum and some other precious metals. As such, is an important raw material for the chemical and pharmaceutical industry. It is mainly used for etching and for the production of pure nitrates. Even though nitric acid was known since the 9th century - alchemists used it to separate gold and silver - its mass production started in 1902 when a German chemist Wilhelm Ostwald developed an industrial process. The German corporation BASF start producing it in an industrial scale by 1915. Initially it was used for the production of explosives but today its main use is for the production of fertilizers such as ammonium nitrate. Other main applications is for the production of explosives, nylon precursors and substituted organic compounds.

In elemental analysis by atomic absorption spectroscopy, ICP, graphite furnace atomic spectroscopy dilute nitric acid is used as a "solvent" for the determination of metal traces in solution.

Let us draw the Lewis dot structure of nitric acid :

Step 1: The central atom will be the N atom since it is the less electronegative (H is a terminal atom – it cannot be a central atom). Connect the atoms with single bonds:

 

Chemistry Net: Electron Dot Structures - Simple Method

Chemistry Net: Simple Procedure for writing Lewis Structures – Le...: "A simple procedure for writing Lewis structures is given in a previous article entitled “Lewis Structures and the Octet Rule”. Relevant wo..."

Simple Procedure for writing Lewis Structures – Lewis Structures for NO2+ and HCN

Lewis Electron Dot Structures of Hydrogen Cyanide (HCN) and Nitronium Ion (NO₂⁺)

A simple procedure for drawing Lewis dot structures was given in a previous post entitled “Lewis Structures and the Octet Rule”.

Several worked examples relevant to this procedure were given in previous posts please see the index page Lewis Structures & the Octet Rule - Theory & Examples . Let us examine the case of nitronium ion NO₂⁺and hydrogen cyanide HCN.

Let us consider the case of NO₂⁺. The Lewis dot structures of NO₂⁺ with formal charges are as follows:

Step 1: The central atom will be the N atom since it is the less electronegative.  Connect the N with the O atoms with single bonds:

Step 2: Calculate the # of electrons in p bonds (pi bonds, multiple bonds) using formula (1) in the article entitled Lewis Structures and the Octet Rule. 

Where n in this case is 3 since NO₂⁺ consists of three atoms. Where V = (6 + 5 + 6) - 1 = 16   Therefore, P = 6n + 2 - V = 6 * 3 + 2 - 16 = 4

Therefore,there are 4 electrons (pi electrons) in NO₂⁺   and 2 double bonds must be added to the structure of Step 1 or 1 triple bond.