Question

How were the number of electrons in the possible Lewis structures of \(\mathrm{CO}_{2}\) calculated?

Short answer

In the Lewis structure of \(\mathrm{CO}_{2}\), there are 16 electrons in total which are distributed accordingly to satisfy the Octet Rule for all atoms - Carbon (C) and Oxygen (O). This number was calculated by adding up the valence electrons: 4 from Carbon and 6 from each Oxygen atom.

Step-by-step solution

Identifying the total number of valence electrons

First, calculate the total number of valence electrons in the given molecule, \(\mathrm{CO}_{2}\). Know that Carbon (C) has 4 valence electrons and Oxygen (O) has 6. But since there are two Oxygen atoms in the molecule, multiply 6 by 2. So, the total number of valence electrons is 4 (from Carbon) + 12 (from 2 Oxygen atoms) = 16.

Distributing the electrons

In a Lewis structure, start placing the electrons from the outside atoms. First, satisfy the Octet Rule for the Oxygen atoms by placing 8 electrons on each (6 are required for an octet, but 2 have already been accounted for by the bonding shared with Carbon). You've used 16 electrons up to this point.

Verifying the Octet Rule

Check the Octet Rule for all atoms. Carbon should also have 8 electrons (4 its own, and 4 from the bonds with Oxygen). Both Oxygen atoms already meet the Octet Rule, as they each have 8 electrons. Therefore, the Lewis structure is correct.

Key concepts

Valence Electrons

Valence electrons are the outermost electrons found in an atom and are responsible for interacting with other atoms. These electrons play a crucial role in forming chemical bonds. For the carbon dioxide (\(\mathrm{CO}_{2}\)) molecule, carbon (C) contributes 4 valence electrons. Each oxygen (O) atom contributes 6 valence electrons. Since \(\mathrm{CO}_{2}\) contains two oxygen atoms, we multiply 6 by 2 to get 12 valence electrons from the oxygen atoms alone. Adding these to the 4 valence electrons from carbon, we have a total of 16 valence electrons available for bonding in the molecule. Understanding valence electrons helps in drawing Lewis structures, predicting molecular shapes, and comprehending the behavior of atoms in a molecule.

Octet Rule

The Octet Rule is a fundamental concept in chemistry that guides the formation of stable molecules. This rule suggests that atoms tend to form bonds until they are surrounded by eight valence electrons, giving them a noble gas-like configuration, which is energetically favorable. In the case of \(\mathrm{CO}_{2}\), each oxygen aims to complete its octet of 8 electrons. Initially, an oxygen atom has 6 valence electrons, so it needs two more to satisfy the octet rule. These are provided through bonding with carbon. Carbon, with its 4 valence electrons, needs 4 more to reach a full octet. By forming double bonds, carbon shares electrons with the two oxygens, achieving stability with 8 electrons in its outer shell, just like oxygen. Thus, the octet rule helps to determine how these atoms share electrons to form a stable molecule.

Chemical Bonding

Chemical bonding is the force that holds atoms together in a molecule. Understanding chemical bonding allows us to explain how atoms stick together to form compounds. In the \(\mathrm{CO}_{2}\) molecule, carbon and oxygen atoms form covalent bonds by sharing electrons. - **Covalent Bonds:** - These bonds occur when atoms share pairs of valence electrons. - In \(\mathrm{CO}_{2}\), carbon forms two double bonds, one with each oxygen atom. These double bonds share two pairs of electrons between the atoms.Covalent bonding explains the stability of the \(\mathrm{CO}_{2}\) molecule, as sharing electrons allows atoms to achieve full outer electron shells, complying with the octet rule. Comprehending how atoms bond chemically leads to a better understanding of molecular structures and reactions.