Chemistry Lewis Dot Structure Calculator

Molecular Structure Calculations

Chemistry Lewis Dot Structure Calculator Worksheet
Chemistry Lewis Dot Structure Calculator Online
Lewis Dot Chemistry
Lewis Dot Structure Chemistry

Every chemistry student has to learn how to draw Lewis Dot Structures. The key is to understand the steps and practice. Lewis Structures are important to learn because they help us predict: the shape of a molecule. How the molecule might react with other molecules. The physical properties of the molecule (like boiling point, surface tension, etc.).

Follow these simple steps to correctly draw a Lewis dot structure: Add up the total number of valence electrons found in the entire compound. Don’t forget to include any positive or negative charges when determining this. Draw the simple structure (skeleton structure) of the compound by connecting everything with single bonds only.
As of 07/12/05 there are 1056 structures in the database. A Best Lewis Structure and Donor Acceptor Interactions Tutorial is available to help you interpret those output sections. These Lewis structure calculations are done using NBO Analysis. Answer some Study Questions to help your understanding of some interesting chemistry.

Colby Chemistry, Paul J. Schupf Computational Chemistry Lab

The simple theories of bonding that we learn in General Chemistry are powerfuland useful. These theories, which include Lewis structures, VSEPR, andhybridization, are simple models that help predict chemicalproperties. However, Lewis dot structures and hybridization are approximationsthat may or may not match reality. We should verify the usefulness of oursimple predictions with molecular orbital theory. If thetheoretical calculations are done carefully, we can learn a lot about chemical structure by comparing our Lewis structures and hybridizationarguments with the molecular orbitals.

The calculations in this database includebond lengths, angles, atomic charges, the dipole moment,bond orders, and molecular orbital energies. The best Lewis structure thatfits the molecular orbitals is also calculated, so you can directlycompare with your predictions. This best Lewis structure is presented withformal electron pair localized bonds and the hybridization of the atomicorbitals used to form these localized bonds. The Chime plugin is neededto see the 3-D structure of the molecules in these pages. See thelink at the bottom of the page for the Chime plugin.

Molecular orbital theory is based on approximations also. These calculationsare done with some of the best available calculation methods (DFT forgeometry and molecular orbital energies and ab initio for properties).We use Alain St-Amant's DeFT program (University of Ottawa).

The Molecular Structure Input Form, see below, will allow you to do calculationsfor molecules not in the database.These calculations take time; 1-2 hours in some cases.

You can use the Formula Search page or browse the links below. As of 07/12/05 there are 1056structures in the database.
A Best Lewis Structure and Donor Acceptor Interactions Tutorialis available to help you interpret those output sections. These Lewisstructure calculations are done using NBO Analysis.
Answer some Study Questions to help your understanding of some interesting chemistry.

Example Molecular Orbital Results

LiHLiFLiClLiOHLiCNLiBrC₂N₂NOO₂COF₂

Many More Diatomic molecules and ions

H₃⁺Li₂OBeH₂BeCl₂diboraneBH₃BH₂CNBH₂SH
BF₃BF₃2-BF₄⁺BF₂O^-BCl₃BH₃NH₃BH₃COBH₃PH₃BO₂NO
C₃C₅H₂OH₃O⁺H₄O⁺O₃O₄CO₂OCScyclic CO₂CO₂^-HCO⁺HOC⁺
N₃ radicalN₃ quartetHN₃N₃^-NCOHNCNHCNNO
NO₂NO₂⁺NO₂^-HOONNOO^-NO₂^- triplet NO₂²⁺NO₃^-NO₃^-triplet NO₂O^-
N₂Ocyclic N₂Ocyclic N₂O₂N₂O₄NO₂NO
ONOOHN₂H₂N₂H₂ tripletH₂NNH₂NN tripletNH₂FNHF₂NF₃NF₄^-N₂F₂N₂F₄BNHF
HNCl⁺NH₂ClN₃ClNCl₂NCl₃NOClONClNClOClNO₂ClNOOt-ClONOOCl₂
OF₂FOO•FOOFFNO₂FOONF₃^-Cl₃^-Cl₃FClF₂⁺
AlH₃AlF₃AlCl₃Al₂Cl₆
SiH₄SiH₃SiH₃SiO₂
P₂PCl₃SO₂SO₃SO₃^-SOCl₂SO₂Cl₂ClO₂ClOOClO₂⁺ClO₂^-ClOO^-
FClOFClO₂K₂O

Many More Binary Hydrides and their Anions, Cations, and Radicals
Many More Triatomic molecules and their Anions, Cations, and Radicals
Many More Period 3 Compounds, Al, Si, P, S, and Cl
Many More Period 4 Compounds, Ga, Ge, As, Se, and Br

Acids

Onium Ions:NH

Chemistry lewis dot structure calculator worksheet

₄⁺NH₃F⁺NH₃Cl⁺H₃O⁺H₃O₂⁺H₂F⁺PH₄⁺H₃S⁺H₂Cl⁺H₂CN⁺
Hydrides:HFHClHCNHCN tripletHNCHNCOHOCNHONCHCNOHNCSHSCNHN₃
H₂N₂H₂N=NN₂H₄H₂O₂P₂H₄H₂SH₂

Chemistry lewis dot structure calculator cheat

S₂
Oxyacids:H₂CO₃HONHNOHNO₂HNO₃H₂O₂

Chemistry Lewis Dot Structure Calculator Worksheet

HOFHOCl
HClO₃HClO₄H₃PO₂H₃PO₃H

₃PO₄HSOHH₂SO₃H₂SO₄

Anions

Hydride Conjugates:F^-Cl^-OH^-CN^-NCO^-CNO^-NCS^-CNS^-NSC^-N₃^-HN₂^-N₂H₃^-HOO^-
P₂H₃^-HS^-
Oxyanions:HCO₃^-CO₃^2-CO₃OH^-CO₃O^2-NO^-NO₂^-NO₃^-HO₂^-O₂^2-OF^-OCl^-ClO₂^-
ClO₃^-ClO₄^-H₂PO₂^-H₂PO₃^-H₂PO₄^-HPO₄^2-PO₄^3-HOS^-HSO^-
HSO₃^-SO₃^2-HSO₄^-SO₄^2-S₂O₃^2-

Many MoreHydroxyl Compounds, Donor-Acceptor Oxides, Oxyacids, and Anions
Many MoreFormally Double Bonded Hydroxyl Compounds, Donor-Acceptor Oxides, and Oxyacids (e.g.Carbonic and Nitric acid)

Organics

ethaneethyleneacetyleneH₂C=C, vinylidene
methanolformaldehydeformic acidmethylamineCF₃Cl

Many More Carbon Compounds, Organics, and Organic Reagents
Many MoreOrganic Radical Cations, Neutral Radicals, Cations, and Anions

Oxides

NH₃->OCH₃NH₂->OCH₂NH->OCH₃OH->OCH₂O->OCH₂O->O tripletH₂N₂->O
PH₃->OCH₃PH₂->OH₂S->OCH₃SH->OCH₃F->OCH₃OFCH₃Cl->OH₂S->O₂

Reactive Intermediates

OH radicalHOO radicalH₂O₂⁺ radicalHCO₃ radicalCO₃^- radical CO₃OH^-CO₃O^2-peroxodicarbonate dianion, O₂COOCO₂^2-
methylene singlet (CH₂)methylene triplet (CH₂)methyl radical (CH₃)CH₃⁺
ethyl radical (CH₃CH₂)CH₃CH₂⁺ethylene tripletcyclopropane radicalHCC•HCC^-
CH₃NH^-CH₃OH⁺CH₃OH₂⁺CH₃O^-CH₃O radicalCH₂OH⁺CH₃CO⁺CH₂CHO^-
CF₂ singletCF₂ tripletCF₃•CF₃⁺CCl₂ singletCCl₂ triplet
CHCl singletCHCl tripletCHBr singletCHBr triplet
H₂CF⁺CH₂Cl⁺CH₂Cl^-trans-C₂H₄Cl₂⁺Cl₂C=C singlet
allyl⁺allyl radicalallyl^-allylalcoholradicalallylchloride radical1-chloropropane radical
HCONH^-N₃ radicalN₃³⁺ singlet N₃³⁺ triplet N₂H⁺

Hydrogen Bonded and Neutral Complexes

H₂O dimerNH₃ dimerHF...waterHF...NH₃HCl...NH₃H₂O...H₂SH₂S...H₂OSO₂...H₂OH₂O...formaldehyde
HCN...formaldehydeHCN...H₂CCwater...COwater...HPO₂CO₂...H₂CO₂

Chemistry Lewis Dot Structure Calculator Online

...CO₂
CO₂...waterH₂O...SO₃H₂S...SO₃PCl₃...Cl₂Cl₂...Cl₂CH₃radical...H₂

H₂O...Cl•

Ion-Molecule Complexes

Li⁺..H₂OLi⁺..(H

Lewis Dot Chemistry

₂O)₂BeCl₂²⁺water...superoxide^-
Be²⁺...H₂C=CH₂ unsymmetricalBe²⁺...H₂C=CH₂ symmetricalBe⁺...H₂C=CH₂ unsymmetricalBe⁺...H₂C=CH₂ symmetrical
FHF^-CO₂F^-H₂...OH^-water...HCONH^-O₃...Br^-
H₃O⁺...H₂OH₃O⁺...CO₂H₃O⁺...N₂H₃O⁺...HO•NO⁺...H₂ONO⁺...N₂NO⁺...O₂

Atomic and Ionic Energies

atomic energiescation energiesanion energies

Weird, Wacky, High Energy Structures

HCl^-

Lewis Dot Structure Chemistry

H₃ClCH₄²⁺COH₂CH₂..HClCH₃OHCH⁺HNCO-cyclicC₄N₂CO₂O^2-CO₂^2-BH₄⁺AlH₄⁺FClPClPF₄⁺F^-ClF₄^-

Go to the

Molecular Structure Input Form

Get your

Results Here

SRC='http://www.colby.edu/chemistry/OChem/buttons.dir/chime.GIF'ALIGN='BOTTOM'>

This work was supported by an Academic Research Infrastructure Grant from the National Science Foundation, no. 9512457.Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

About the calculation methods

Covalent Lewis Dot Structures

A bond is the sharing of 2 electrons.

Covalent bonds share electrons in order to form a stable octet around each atom in the molecules. Hydrogen is the exception it only requires 2 electrons (a duet) to be stable.

How do we draw a covalent Lewis Dot Structure?

Level 1 (basic)

1. Add up all the valance electrons of the atoms involved. ex CF₄

So C has 4 and F has 7 (x4 we have 4Fs) = 32 valence electrons

2. You need to pick the central atom. This is usually easy, this atom will be surrounded by the others. Never H.

So C will be surrounded by F's.

3. Now we create our skeleton structure by placing bonds in. A bond is a dash that represents 2 electrons.

We have now placed 8 electrons as 4 bonds. We have 32-8= 24 more to place.

4. Starting with the outer atoms add the remaining electrons in pairs until all the electrons have run out.

All 32 electrons are now in place, count the dots around each F. 6 dots and a bond (2 electrons) is 8. We have our octet.

The carbon has 4 bonds (2electrons) for its 8.

DONE

Level 2 (Double and Triple bonds)

Same rules apply until #4

1. Add up all the valance electrons of the atoms involved. ex CO₂

So C has 4 and O has 6 (x2 ) = 16 valence electrons

2. You need to pick the central atom. This is usually easy, this atom will be surrounded by the others. Never H.

So C will be surrounded by O's.

3. Now we create our skeleton structure by placing bonds in. A bond is a dash that represents 2 electrons.

We have now placed 4 electrons as 2 bonds. We have 16-4=12 more to place.

4. Starting with the outer atoms add the remaining electrons in pairs until all the electrons have run out.

All 16 electrons are now in place, count the dots around each O. 6 dots and a bond (2 electrons) is 8. We have our octet.

The carbon has 2 bonds (2electrons) for its 4....?

We need 8, so move a pair of electrons from the O to between the C and O. It will share 2 pairs of electrons instead of 1. It now has a double bond instead of a single bond.

carbon has 6 electrons, so move 2 from the other oxygen

now they all have an octet, it cleans up like this

Make it symmetrical.

Level 3-Lewis Dots of Polyatomic Ions

Same rules apply, at the end they get brackets and a charge

AP Chemistry and or College Level Rules

1. Determine whether the compound is covalent or ionic. If covalent, treat the entire molecule. If ionic, treat each ion separately. Compounds of low electronegativity metals with high electronegativity nonmetals (DE_N> 1.7) are ionic as are compounds of metals with polyatomic anions. For a monoatomic ion, the electronic configuration of the ion represents the correct Lewis structure. For compounds containing complex ions, you must learn to recognize the formulas of cations and anions.

2. Determine the total number of valence electrons available to the molecule or ion by:

(a) summing the valence electrons of all the atoms in the unit and
(b) adding one electron for each net negative charge or subtracting one electron for each net positive charge. Then divide the total number of available electrons by 2 to obtain the number of electron pairs (E.P.) available.

3. Organize the atoms so there is a central atom (usually the least electronegative) surrounded by ligand (outer) atoms. Hydrogen is never the central atom.

4. Determine a provisional electron distribution by arranging the electron pairs (E.P.) in the following manner until all available pairs have been distributed:

a) One pair between the central atom and each ligand atom.
b) Three more pairs on each outer atom (except hydrogen, which has no additional pairs), yielding 4 E.P. (i.e., an octet) around each ligand atom when the bonding pair is included in the count.
c) Remaining electron pairs (if any) on the central atom.

5. Calculate the formal charge (F) on the central atom.

a) Count the electrons shared as bonds. Total = b
b) Count the electrons owned as lone pairs. Total = n
c) F = V - (n + b/2), where V = number of valence electrons for the atom.

6. If the central atom formal charge is zero or is equal to the charge on the species, the provisional electron distribution from (4) is correct. Calculate the formal charge of the ligand atoms to complete the Lewis structure.

7. If the structure is not correct, calculate the formal charge on each of the ligand atoms. Then to obtain the correct structure, form a multiple bond by sharing an electron pair from the ligand atom that has the most negative formal charge.

a) For a central atom from the second (n = 2) row of the periodic table continue this process sequentially until the central atom has 4 E.P. (an octet).
b) For all other elements, continue this process sequentially until the formal charge on the central atom is reduced to zero or two double bonds are formed.

8. Recalculate the formal charge of each atom to complete the Lewis structure.

on to Formal Charge

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