C5H12 Lewis structure

C5H12 Lewis Structure
C5H12 Lewis structure | Image: Learnool

C5H12 (pentane) has five carbon atoms and twelve hydrogen atoms.

In the C5H12 Lewis structure, there are four single bonds between the five carbon atoms. The left carbon and right carbon are attached with three hydrogen atoms, and the three center carbons are attached with two hydrogen atoms. And none of the atoms has a lone pair.


Here’s how you can easily draw the C5H12 Lewis structure step by step:

#1 Draw a rough skeleton structure
#2 Mention lone pairs on the atoms
#3 If needed, mention formal charges on the atoms

Now, let’s take a closer look at each step mentioned above.

#1 Draw a rough skeleton structure

  • First, determine the total number of valence electrons
Periodic table | Image: Learnool

In the periodic table, carbon lies in group 14, and hydrogen lies in group 1.

Hence, carbon has four valence electrons and hydrogen has one valence electron.

Since C5H12 has five carbon atoms and twelve hydrogen atoms, so…

Valence electrons of five carbon atoms = 4 × 5 = 20
Valence electrons of twelve hydrogen atoms = 1 × 12 = 12

And the total valence electrons = 20 + 12 = 32

  • Second, find the total electron pairs

We have a total of 32 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 32 ÷ 2 = 16

  • Third, determine the central atom

Here hydrogen can not be the central atom. Because the central atom is bonded with at least two other atoms, and hydrogen has only one electron in its last shell, so it can not make more than one bond.

Now there are five atoms remaining and all five atoms are carbon, so we can assume any one as the central atom.

Let’s assume that the central atom is right carbon.

Therefore, place carbons in the center and hydrogens on either side.

  • And finally, draw the rough sketch
C5H12 Lewis Structure (Step 1)
Rough sketch drawn, and got the stable Lewis structure of C5H12 | Image: Learnool

#2 Mention lone pairs on the atoms

Here, we have a total of 16 electron pairs. And sixteen bonds are already marked. So we do not have to mark any electron pair as a lone pair on the sketch.

In the above structure, you can see that the central atom (right carbon) forms an octet. The outside atoms (other carbons) also form an octet, and all hydrogens form a duet. Hence, the octet rule and duet rule are satisfied.

Therefore, this structure is the stable Lewis structure of C5H12.

Next: XeF6 Lewis structure


Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.

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