# C3H8 Lewis structure

C3H8 (propane) has three carbon atoms and eight hydrogen atoms.

In the C3H8 Lewis structure, there are two single bonds between the three carbon atoms. The left carbon and right carbon are attached with three hydrogen atoms, and the center carbon is attached with two hydrogen atoms. And none of the atoms has a lone pair.

Contents

## Steps

To properly draw the C3H8 Lewis structure, follow these steps:

#1 Draw a rough sketch of the structure
#2 Next, indicate lone pairs on the atoms
#3 Indicate formal charges on the atoms, if necessary

Let’s break down each step in more detail.

### #1 Draw a rough sketch of the structure

• First, determine the total number of valence electrons

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 C3H8 has three carbon atoms and eight hydrogen atoms, so…

Valence electrons of three carbon atoms = 4 × 3 = 12
Valence electrons of eight hydrogen atoms = 1 × 8 = 8

And the total valence electrons = 12 + 8 = 20

• Second, find the total electron pairs

We have a total of 20 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 = 20 ÷ 2 = 10

• 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 three atoms remaining and all three atoms are carbon, so we can assume any one as the central atom.

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

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

• And finally, draw the rough sketch

### #2 Next, indicate lone pairs on the atoms

Here, we have a total of 10 electron pairs. And ten 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 (center carbon) forms an octet. The outside atoms (left carbon and right carbon) 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 C3H8.