(a) Draw Lewis structures for chloromethane 1CH3Cl2, chloroethene 1C2H3Cl2, and chloroethyne 1C2HCl2. Draw Lewis structures for chloroethyne 1C2HCl2.

Verified step by step guidance

1. Identify the total number of valence electrons for each molecule. For chloromethane (CH3Cl), add the valence electrons of carbon (4), three hydrogens (1 each), and chlorine (7). For chloroethene (C2H3Cl), add the valence electrons of two carbons (4 each), three hydrogens (1 each), and chlorine (7). For chloroethyne (C2HCl), add the valence electrons of two carbons (4 each), one hydrogen (1), and chlorine (7).
2. Arrange the atoms in each molecule. In chloromethane, carbon is the central atom with three hydrogens and one chlorine attached. In chloroethene, the two carbons form a double bond, with two hydrogens attached to one carbon and one hydrogen and one chlorine attached to the other carbon. In chloroethyne, the two carbons are connected by a triple bond, with one hydrogen attached to one carbon and chlorine attached to the other carbon.
3. Complete the octets of the surrounding atoms using lone pairs. In chloromethane, ensure that chlorine has three lone pairs. In chloroethene, ensure that the chlorine has three lone pairs and the carbon with one hydrogen has no lone pairs. In chloroethyne, ensure that the chlorine has three lone pairs.
4. Check the formal charges to ensure the most stable structure. All atoms should ideally have a formal charge of zero, adjusting lone pairs if necessary.
5. Draw the Lewis structures based on the above steps, showing all valence electrons as either bonding pairs or lone pairs around each atom.

Key Concepts

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They use dots to represent electrons and lines to represent bonds between atoms. Understanding how to draw Lewis structures is essential for visualizing molecular geometry and predicting the reactivity of compounds.

Valence Electrons

Valence electrons are the outermost electrons of an atom and are crucial in determining how atoms bond with each other. The number of valence electrons influences the type of bonds formed (single, double, or triple) and the overall structure of the molecule. Knowing how to count and distribute valence electrons is key to accurately drawing Lewis structures.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is influenced by the number of bonds and lone pairs around the central atom, which can affect the molecule's physical and chemical properties. Understanding molecular geometry helps in predicting the behavior of molecules in reactions and their interactions with other substances.