What is the Lewis structure for CH3CH(CH3)CH2CHO?
The correct answer and explanation is :
The molecule CH3CH(CH3)CH2CHO is commonly known as 3-methylbutanal. The Lewis structure for this compound is derived by following the rules of covalent bonding and electron distribution. Let’s break it down:
Step-by-Step Explanation:
- Identify the atoms and bonds:
- CH3 (methyl group): A group consisting of one carbon (C) bonded to three hydrogens (H).
- CH (methylene group): A carbon (C) attached to a hydrogen (H) and another methyl group (CH3).
- CH2 (methylene group): A carbon (C) bonded to two hydrogens (H).
- CHO (aldehyde group): This consists of a carbonyl group (C=O) attached to a hydrogen (H). This is the terminal group, making it an aldehyde.
- Count the valence electrons:
- Carbon (C) has 4 valence electrons.
- Hydrogen (H) has 1 valence electron.
- Oxygen (O) has 6 valence electrons. The total number of valence electrons in CH3CH(CH3)CH2CHO is calculated as follows:
- 4 carbon atoms × 4 electrons = 16 electrons.
- 8 hydrogens × 1 electron = 8 electrons.
- 1 oxygen atom × 6 electrons = 6 electrons. Total valence electrons = 16 + 8 + 6 = 30 electrons.
- Structure Construction:
- Place the carbon atoms as the backbone, with single bonds between them.
- Start by connecting the two methyl groups (CH3) to the second and third carbon atoms.
- The central carbon (attached to the two methyl groups) bonds to a CH2 group, which is connected to the terminal aldehyde group (CHO).
- The oxygen in the aldehyde group forms a double bond with the terminal carbon.
- Electron Pair Distribution:
- Hydrogen atoms are placed around each carbon to ensure all carbons follow the octet rule.
- The aldehyde group carbonyl (C=O) is double bonded to oxygen, with the remaining hydrogen atom attached to the same carbon.
- Resulting Lewis Structure:
- The final structure looks like this:
H H
| |
CH3-C-CH2-CHO
|
CH3
Where the carbon atoms are bonded with single and double bonds, the hydrogens are appropriately placed to fulfill the octet rule, and the oxygen in the aldehyde group has a double bond to carbon.
Conclusion:
The Lewis structure of CH3CH(CH3)CH2CHO places the atoms in a way that respects the valence electron requirements, with the aldehyde group (C=O) as the functional group. Each carbon atom follows the octet rule by bonding with hydrogen atoms and other carbon atoms.