Draw a Lewis diagram for CH
C
H. • Remember to include all valence lone pairs in your answer.
The Correct Answer and Explanation is:
Correct Lewis Structure for CH₃CH₃ (Ethane):
Let’s first draw the Lewis structure of CH₃CH₃:
H H
\ /
H - C - C - H
/ \
H H
Each carbon atom (C) forms 4 covalent bonds to satisfy the octet rule. Each hydrogen atom (H) forms 1 single bond (as it only needs 2 electrons to be stable). In CH₃CH₃:
- Each C is bonded to three H atoms and one C atom.
- Each H is bonded to one C.
There are no lone pairs on any of the atoms in this molecule.
Step-by-Step Explanation
CH₃CH₃, commonly known as ethane, is a simple alkane made of carbon (C) and hydrogen (H) atoms. To draw its Lewis structure, follow these steps:
- Count the total valence electrons:
- Carbon (C) has 4 valence electrons.
- Hydrogen (H) has 1 valence electron.
- There are 2 carbon atoms and 6 hydrogen atoms:
- Total = (2 × 4) + (6 × 1) = 8 + 6 = 14 valence electrons.
- Determine the central atoms:
- The two carbon atoms are central and bonded to each other.
- Each carbon is then surrounded by 3 hydrogen atoms.
- Connect atoms with single bonds:
- Each C–H bond uses 2 electrons.
- Each C–C bond uses 2 electrons.
- So, there are 6 C–H bonds and 1 C–C bond:
- Electrons used = (6 × 2) + (1 × 2) = 12 + 2 = 14 electrons.
- Check the octet rule:
- Each carbon has 4 bonds (8 electrons): satisfies the octet rule.
- Each hydrogen has 1 bond (2 electrons): satisfies the duet rule.
- Assign lone pairs:
- All 14 valence electrons are used in bonding.
- Therefore, there are no lone pairs on any atom in CH₃CH₃.
Conclusion:
The Lewis structure of ethane (CH₃CH₃) features all atoms with complete outer shells, all bonds are single covalent bonds, and no lone pairs exist in this molecule. It’s a typical saturated hydrocarbon (alkane).
