The correct lewis structure for COH2 contains how many covalent bonds?
The Correct Answer and Explanation is :
The correct Lewis structure for formaldehyde (COH₂, also known as methanal) contains four covalent bonds. This includes two single bonds between carbon and each hydrogen atom, and a double bond between carbon and oxygen.
Explanation:
- Atoms involved: Formaldehyde (COH₂) consists of:
- 1 carbon (C) atom
- 2 hydrogen (H) atoms
- 1 oxygen (O) atom
- Valence electrons: To draw the Lewis structure, it is crucial to account for the total number of valence electrons. The valence electrons are as follows:
- Carbon (C) has 4 valence electrons.
- Oxygen (O) has 6 valence electrons.
- Each hydrogen (H) has 1 valence electron, and there are two hydrogens, contributing a total of 2 electrons. Total number of valence electrons = 4 (C) + 6 (O) + 2 (2H) = 12 valence electrons.
- Bonding: Carbon is the central atom because it can form multiple bonds. Hydrogen atoms form single bonds since they only need two electrons (one bond) to complete their valence shell. Oxygen forms a double bond with carbon to fulfill its octet, as it needs two additional electrons to reach eight in its outer shell.
- Lewis structure:
- Carbon forms two single bonds with two hydrogen atoms.
- Carbon forms a double bond with oxygen.
- Oxygen has two lone pairs of electrons remaining to fulfill the octet rule.
This arrangement uses all 12 valence electrons (4 bonds, which account for 8 electrons, plus the 4 electrons in oxygen’s lone pairs). Each atom fulfills its electron needs, with carbon forming a total of four covalent bonds—two single bonds with hydrogen and one double bond with oxygen.
Thus, the Lewis structure of formaldehyde includes four covalent bonds.