Draw a correct Lewis structure for chloromethane, CH3Cl.
The correct answer and explanation is:
The Lewis structure of chloromethane (CH₃Cl) can be drawn by following these steps:
- Count the total number of valence electrons:
- Carbon (C) has 4 valence electrons.
- Hydrogen (H) has 1 valence electron, and there are 3 hydrogen atoms.
- Chlorine (Cl) has 7 valence electrons.
- Arrange the atoms:
Carbon is the central atom because it can form four bonds. Chlorine and hydrogen atoms will be bonded to carbon. Hydrogen atoms are always placed on the outer positions as they can only form one bond. - Connect the atoms with single bonds:
- Place the carbon atom in the center.
- Draw single bonds (a line representing 2 electrons) between the carbon atom and each of the three hydrogen atoms, and between the carbon atom and the chlorine atom.
- Distribute the remaining electrons:
After placing the single bonds, each bond uses 2 electrons. Since 4 bonds are drawn, 4×2=84 \times 2 = 8 electrons are used. This leaves 14−8=614 – 8 = 6 electrons. - Complete the octets:
- Chlorine needs to have 8 electrons around it. Since chlorine is already sharing one pair of electrons with carbon, it only needs 3 lone pairs (6 electrons) to complete its octet.
- Carbon has 8 electrons around it from the 4 bonds, fulfilling its octet requirement.
- Hydrogen atoms have 2 electrons each from their single bonds with carbon, so they are satisfied with their duet.
The final Lewis structure of CH₃Cl looks like this:
H
|
H - C - Cl
|
H
In this structure:
- Carbon (C) is in the center with 4 bonds (one to each hydrogen atom and one to chlorine).
- Chlorine (Cl) has 3 lone pairs of electrons to complete its octet.
- Each hydrogen (H) has 2 electrons from its single bond with carbon, completing its duet.
This is the correct Lewis structure for chloromethane, CH₃Cl.