Question

Draw three resonance structures for the sulfine molecule, \(\mathrm{H}_{2} \mathrm{CSO}\). Do not consider ring structures.

Short answer

The 3 resonance structures for the H2CSO molecule are: H2C-S=O, H2C=S-O, and H2C-S=O.

Step-by-step solution

Draw the Lewis Structure

First, a Lewis structure needs to be drawn for the sulfine molecule, H2CSO. One can start by putting Sulfur (S) at the center, being the least electronegative atom and having the capability to form more bonds, then arrange Carbon (C) and Oxygen (O) around it. Next is to connect Hydrogen (H) atoms to the Carbon (C) since Hydrogen can only form one bond.

Distribute electrons

Remembering each bond represents two shared electrons and that the sum of the valence electrons for H2CSO is 18, arrange the remaining electrons so that every atom follows the octet rule - having eight electrons in its outer shell. Carbon will form a double bond with Sulphur. Distribute the remaining electrons equally between Sulphur and Oxygen.The initial Lewis structure should look like this:H-C=S=O (Sulphur and Oxygen both have two lone pairs of electrons)

Generate Resonance Structures

Now to generate resonance structures, the idea is to shift electrons not atoms. The two electrons can be moved to form a double bond between Sulphur and Oxygen and that would break the π bond between Carbon and Sulphur moving two electrons down to Sulphur and forming a lone pair.The first resonance structure is: H2C-S=OFor the second resonance structure, the opposite can be done by forming a double bond between Carbon and Sulphur which breaks the π bond between Sulphur and Oxygen moving two electrons down to Oxygen and forming a lone pair. The second resonance structure is: H2C=S-OFor the third resonance structure, a lone pair of electrons from Oxygen can form a double bond with Sulphur, breaking the π bond between Sulphur and Carbon and moving two electrons down to Sulphur. The third resonance structure is: H2C-S=O

Key concepts

Lewis Structure

Understanding the Lewis structure is crucial when dealing with molecules like sulfine (\(\mathrm{H}_{2}\mathrm{CSO}\)). A Lewis structure is a diagram that displays the bonds between atoms and the lone pairs of electrons in a molecule.

• To draw the structure, arrange the atoms to reflect their electronegativities and bonding capabilities. In H2CSO, the Sulfur (\(\mathrm{S}\)) atom is typically placed at the center because it can handle multiple bonds, while Carbon (\(\mathrm{C}\)) and Oxygen (\(\mathrm{O}\)) are positioned around it.
• Hydrogen atoms always bond with Carbon. Keep in mind that each bond consists of two electrons, representing a shared pair between atoms.
• The total number of valence electrons on the molecule should be calculated - for H2CSO, this is 18 electrons.

Distribute these electrons such that each atom satisfies its valence: Hydrogen wants two electrons, while elements like Carbon, Sulfur, and Oxygen typically follow the octet rule.

Sulfine Molecule

Sulfine, also denoted as \(\mathrm{H}_{2}\mathrm{CSO}\), is a small molecule with an interesting central structure. The molecule consists of:

• Two Hydrogen (\(\mathrm{H}\)) atoms bonded to a Carbon (\(\mathrm{C}\)) atom, following Hydrogen's propensity to form single bonds.
• A central Sulfur (\(\mathrm{S}\)) atom, which can participate in multiple bonding due to its valence electron configuration.
• An Oxygen (\(\mathrm{O}\)) atom that often forms two bonds and likes to keep lone pairs.

The sulfine molecule is an excellent example for studying resonance structures as it can exhibit different electron arrangements.Through resonance, it's possible to move bond electrons, particularly around Sulfur, Carbon, and Oxygen. The flexibility in \(\mathrm{H}_{2}\mathrm{CSO}\) allows examining the distribution of the shared and lone pair electrons to create distinct, yet valid arrangements.

Octet Rule

The octet rule is an essential concept in chemistry for understanding molecular structures. It states that atoms are most stable when they have eight electrons in their valence shell.

• For molecules like H2CSO, ensuring that each atom conforms to the octet rule is crucial during Lewis structure formation.
• Hydrogen is an exception, requiring only two electrons to achieve stability.
• Carbon, Sulfur, and Oxygen generally form bonds to complete their octet, with Carbon typically making four bonds.

To resolve resonance structures in sulfine, consider how bond rearrangements can still satisfy the octet rule. For example, by moving electrons between \(\mathrm{S}\) and \(\mathrm{O}\) or \(\mathrm{C}\), the participating atoms can maintain a complete valence shell, illustrating the importance of this rule in predicting stable molecular configurations.