CH4 Lewis Structure: 5 Easy steps to Draw With Image & Shape

Reviewed by Manjula Sivapuri

The common name of CH4 is methane. It is the simplest hydrocarbon in the organic molecule and it is a hydride of C. In the CH4 lewis structure, the molecule is a tetrahedral shape and has a bond angle of perfectly 109.50.  The molecule undergoes is sp3 hybridization. One H atom is below the molecular plane and the other is above the molecular plane.

CH4 is used to synthesize higher-order hydrocarbon in organic reactions. It is a simple alkane because all the C-H bonds are single.

How to draw the CH4 Lewis structure?

Drawing the Lewis structure for methane (CH4) is pretty straightforward, but let’s walk through the process step-by-step. Methane is a simple molecule, consisting of one carbon atom bonded to four hydrogen atoms. Here’s how you can draw its Lewis structure:

CH4 Lewis Structure: Steps

Count the Total Number of Valence Electrons: In methane, the central carbon atom has 4 valence electrons, and each hydrogen atom has 1 valence electron. Since there are 4 hydrogen atoms, that’s 4 valence electrons from hydrogen, plus the 4 from carbon, giving us a total of 8 valence electrons to work with.

Determine the Central Atom: Carbon is less electronegative than hydrogen, and it can form more bonds, so carbon will be the central atom in the structure.

Sketch a Skeleton of the Molecule: Place carbon in the center and arrange the four hydrogen atoms around it. It’s like picturing a plus sign, with carbon at the intersection and hydrogen atoms at the ends of each line.

CH4 Lewis Structure: Step 1

Distribute the Valence Electrons: Starting with the outer atoms, place electrons around them to represent the bonds between the carbon and hydrogen atoms. Each bond between carbon and hydrogen will use 2 of the 8 valence electrons. Since we have 4 C-H bonds in methane, all 8 electrons are used up in forming these bonds.

CH4 Lewis Structure: Step 2

Check the Octet Rule: Every atom in methane follows the rules they love to live by. Carbon gets its full octet because it shares 4 electrons with hydrogen (one from each bond), and each hydrogen is happy with 2 electrons (a full outer shell for hydrogen).

CH4 Lewis Structure: Step 3

Add Lone Pairs if Necessary: In the case of methane, there are no lone pairs because we used all the valence electrons in forming bonds, and every atom has its required full outer shell.

So, final CH4 Lewis Structure is:

That’s it! You’ve got the Lewis structure for methane. Visually, you’d see the carbon in the center with single lines (representing single bonds) stretching out to the hydrogens at the four compass points. Methane’s structure is a perfect example of a tetrahedral molecular geometry, but that’s diving a bit into molecular shapes.

CH4 lewis structure shape

According to the VSEPR (Valence Shell Electrons Pair Repulsion) theory if the electrons count of any molecule is 8 then the molecule adopts tetrahedral geometry. The electrons contribution for C is 4 and four H atoms contribute 1 electron each, so the total electron count will be 8. So, the CH4 lewis structure is tetrahedral.

image 56
CH4 Lewis Shape

In the CH4 lewis structure, the whole electron density lies over the central C atoms only. The C is surrounded by four H atoms in the tetrahedral moiety. The shape of the molecule is ideal and no deviation in the shape and geometry because there is no lone pair present and no destabilization factor is present too.

CH4 valence electrons

The electrons present at the valence or outermost shell of an atom are known as valence electrons. For C the number of valence electrons is 4 and for H the number of valence electrons is 1.

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CH4 Valence Electrons

In the CH4 lewis structure, the C atom is a Group 14th element, having electronic configuration [He]2s22p2 so, it has four electrons in its outermost orbital and all the electrons are involved in the sigma bond formation with four H atoms. For H atom we all know only one electron is present and that is its valence electron and it is involved in the bond formation with C.

So, in the CH4 lewis structure, the total number of valence electrons is 4+(4*1) = 8 electrons and it is shown that the number octet is fully satisfied by this molecule.

CH4 lewis structure formal charge

Accounting for the same electronegativity for all the atoms in a particular molecule calculates the specific charge over the molecule or individual atoms is called the formal charge. The formal charge is a hypothetical concept, by this concept, we can predict whether the molecule is charged or not.

The formula we can use to calculate the formal charge, F.C. = Nv – Nl.p. -1/2 Nb.p.

Where Nv is the number of electrons in the valence shell or outermost orbital, Nl.p is the number of electrons in the lone pair, and Nb.p  is the total number of electrons that are involved in the bond formation only.

In the CH4 lewis structure, C and H are different substituents so we calculate the formal charge of C and H individually.

The formal charge over C is, 4-0-(8/2) = 0

The formal charge over H is, 1-0-(2/2) = 0

So, the formal charge over C as well as H is zero. It is also reflected that in the CH4 lewis structure that the molecule is also neutral.

So, the individual formal charge also gives the proper explanation of a charged or neutral molecule.

CH4 lewis structure lone pairs

The electrons are present at the valence shell or outermost orbital of an atom but are not involved in direct bond formation but exist as pairs are called lone pairs. From the CH4 lewis structure, we can say there are no lone pairs over the molecule.

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CH4 Lone Pairs

In the CH4 lewis structure, there are two substituents present, C and H. H has only one electron in its shell and that electron is also the valence electron for it. That one electron of H is involved in the sigma bond formation with the central c atom, so there is no lone pair for H atom.

C is group 14th element and it has four electrons in its outermost orbital all of the electrons are involved in the sigma bond formation with four H atoms. So, there are no electrons present for C in its outermost orbital. So, C also lacks lone pairs and the whole CH4 lewis structure does not contain any lone pairs.

CH4 lewis structure octet rule

Every atom except noble gas tries to complete its valence shell but accepts a suitable number of an electron from another source and tries to gain the nearest noble gas configuration according to the o octet rule. CH4 lewis structure also tries to complete its octet by bond formation between C and H.

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CH4 Octet

In the CH4 lewis structure, the electronic configuration of C is [He]2s22p2. So, there are four electrons in the outermost shell for C and it needs four more electrons to complete its octet. Now in CH4 molecule C form four sigma bonds with four H atoms via sharing electrons and completing its octet.

Again, for H there is only one electron, and that one electron is the valence electron which is present at the valence shell for H. H needs one more electron to complete its octet and gain the nearest noble gas configuration like He. Now H forms a bond with C via sharing its one electron and one electron from C and completing its octet too.

CH4 lewis structure bond angle

A bond angle is a specific angle made by the atoms in a particular molecule for arranging them in a particular manner. In the CH4 lewis structure, the bond angle is 109.50, which is ideal for tetrahedral geometry.

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CH4 Bond Angle

From the CH4 lewis structure, we know that the methane molecule adopts tetrahedral geometry and from VSEPR theory we know that the bond angle for tetrahedral geometry is 109.50. In this structure, there is no deviation from the ideal bond angle and the reason behind this is that there is no deviation factor present. The size of C, as well as H, are very small so there is no repulsion between them and there are no lone pairs over the molecule. So, no chance of lone pair-bond pair repulsion.

So, the H-C-H is perfectly 109.50 in the ideal tetrahedral moiety.

CH4 lewis structure resonance

Delocalization of electronic clouds in between different skeletons of a particular molecule is called resonance. But in the CH4 lewis structure, there is no resonance occurs.

Resonance occurs among the atoms which lie at the same plane only. But in the CH4 lewis structure, two of the H atoms are present at the molecular plane but another two lie below and above the molecular plane. So, resonance cannot occur there. Again, for resonance, there is a need an extra electronic cloud that can be delocalized but C and H both are electropositive and lack of electronic cloud.

So, in the CH4 lewis structure resonance cannot be occurred. So, there are no resonating structures are observed for the CH4 lewis structure.

CH4 hybridization

Hybridization is a theoretical concept by which two or more orbitals having different energy undergo mixing to produce a hybrid orbital of equivalent energy and form a covalent bond. CH4 lewis structure is a covalent molecule so it also shows hybridization and the central C atom is sp3 hybridized.

We calculate the CH4 hybridization by using the following formula,

H = 0.5(V+M-C+A), where H= hybridization value, V is the number of valence electrons in the central atom, M = monovalent atoms surrounded, C=no. of cation, A=no. of the anion.

For the CH4 lewis structure, c has 4 valence electrons which are involved in the bond formation, and four H atoms are present.

So, the central C in the CH4 lewis structure is, ½(4+4+0+0) = 4 (sp3) hybridized.

Structure   Hybridization value   State of hybridization of central atom   Bond angle
Linear  2sp /sd / pd    1800
Planner trigonal 3sp2             1200
Tetrahedral      4sd3/ sp3      109.50
Trigonal bipyramidal 5sp3d/dsp3         900 (axial), 1200(equatorial)
Octahedral     6sp3d2/ d2sp3         900
Pentagonal bipyramidal7sp3d3/d3sp3              900,720

                  From the above table of hybridization, we can conclude that if the hybridization value is 4 then the central atoms is sp3 hybridized.

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CH4 Hybridization

From the box diagram of the CH4 lewis structure, we can say that in the ground state c is unable to form a bond because there are two electrons paired in the 2s orbital. In the excited state, C formed a bond with four H atoms involving its one s and three p orbitals. So, the mode of hybridization is sp3.

In the hybridization, we only consider the sigma bond, not the double or multiple bonds.

CH4 solubility

From the CH4 lewis structure, we also can predict the solubility of this molecule. The methane molecule is nonpolar so it is mostly dissolved in a nonpolar solvent or organic solvent. But due to H bonding, it is also soluble in polar solvents like water.

From the dipole moment calculation, we see that the molecule is nonpolar so it is expected that it is soluble in benzene, an ethanol-like organic solvent. But in methane molecules there are four H atoms are present and they can easily form H bonding with the lone pair of the water molecule and the molecule gets soluble in water also.

Is CH4 ionic?

According to Fajan’s rule, we can say every covalent molecule shows some % of ionic character.

In the CH4 lewis structure, the size of the C atom is small but the charge density is also less so the ionic potential is very low, so it cannot polarize H properly but the size of the hydride ion is very large. So is a view of ionic potential has some ionic character too.

Is CH4 acidic or basic?

The polarity of a molecule is depend on the value of the resultant dipole moment. For CH4 lewis structure, it is nonpolar due to zero dipole moment.

In the CH4 lewis structure, we can see that all the C-H bonds are equal and they have the same electronegativity difference the structure is symmetrical so four dipole moments cancel out each other and the net result is zero dipole moment for the CH4 molecule and makes the molecule non-polar.

Is CH4 tetrahedral?

Yes, CH4 is a tetrahedral molecule. From VSEPR the total electron count for the methane molecule is 8 and this is the reason the shape of the molecule is tetrahedral.

From the CH4 lewis structure and hybridization, we see that the molecule adopts tetrahedral geometry. The molecule is sp3 hybridized and this is also reflected in the geometry of the molecule tetrahedral.

Some detailed facts about CH4

CH4 is a colorless, odorless, and very lighter gaseous molecule. Every hydrocarbon on combustion produced carbon dioxide, so on combustion of methane also produced carbon dioxide and water vapor. The melting point and boiling point of methane molecule are 90 K and 116 K respectively.

The molecule is synthesized in the presence of Ni catalyst, Hydrogen gas, and carbon monoxide.

CO + 3H2 = CH4 + H2O

Methane is used as fuel in different automobile systems and refined methane is also used as rocket fuel. It readily participates in many radical reactions and forms methyl radical which is a more reactive species.

Conclusion

From the above discussion of CH4 lewis structure, we can say that this molecule is a perfectly tetrahedral molecule and the bond angle is 109.50 and there is no deviation factors present due to C and H both being small in size. Although methane is nonpolar but soluble in water and the methanium ion behaves as a super acid.

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