How many nonbonding electron pairs are there in each of the following molecules: (a) (CH₃)₂S

Verified step by step guidance

1. Identify the central atom in the molecule, which is sulfur (S) in this case.
2. Determine the total number of valence electrons for the central atom. Sulfur has 6 valence electrons.
3. Count the number of bonds formed by the central atom. In (CH_3)_2S, sulfur forms two single bonds with two CH_3 groups.
4. Calculate the number of electrons used in bonding. Each single bond uses 2 electrons, so 2 bonds use 4 electrons.
5. Subtract the number of bonding electrons from the total valence electrons to find the number of nonbonding electrons. Divide this number by 2 to find the number of nonbonding pairs.

Key Concepts

Valence Shell Electron Pair Repulsion (VSEPR) Theory

VSEPR theory is a model used to predict the geometry of individual molecules based on the repulsion between electron pairs in the valence shell of the central atom. According to this theory, electron pairs, whether bonding or nonbonding, will arrange themselves to minimize repulsion, which helps in determining the molecular shape and the presence of lone pairs.

Lone Pairs

Lone pairs are pairs of valence electrons that are not involved in bonding and are localized on a single atom. In molecular structures, these nonbonding electron pairs can influence the shape of the molecule and its reactivity, as they occupy space and can repel bonding pairs of electrons.

Molecular Structure of (CH3)2S

The molecular structure of dimethyl sulfide, (CH3)2S, consists of a sulfur atom bonded to two methyl groups (CH3). The sulfur atom has two lone pairs of electrons, which are crucial for determining the overall shape of the molecule and its polarity. Understanding the arrangement of these atoms and electron pairs is essential for identifying the number of nonbonding electron pairs.