Problem 134 - A Complete Resource Book in Chemistry for JEE Main

Question

Which are the species in which sulphur undergoes \(\mathrm{sp}^{3}\) hybridization? (1) \(\mathrm{SF}_{4}\) (2) \(\mathrm{SCl}_{2}\) (3) \(\mathrm{SO}_{4}^{2-}\) (4) \(\mathrm{H}_{2} \mathrm{~S}\) Select the correct answer using the code given below: (a) 1 and 2 (b) 2,3 and 4 (c) 1,3 and 4 (d) 1,2 and 3

Step-by-Step Solution

Answer

(b) 2, 3, and 4

Step 1: Understand Hybridization Concepts

Hybridization is a concept used to explain the shape and bonding properties of an atom in a compound. When we say sulphur undergoes \(sp^3\) hybridization, it means sulphur has mixed one s and three p orbitals to form four equivalent hybrid orbitals.

Step 2: Determine Hybridization for Each Species

We examine each sulphur compound one by one to determine its hybridization: - \(\mathrm{SF}_4\): Sulphur has one lone pair and forms four bonds with fluorine, which results in \(sp^3d\) hybridization, not \(sp^3\). - \(\mathrm{SCl}_2\): Sulphur has two lone pairs and forms two bonds with chlorine (total 4 electron domains), which results in \(sp^3\) hybridization. - \(\mathrm{SO}_4^{2-}\): Sulphur forms four bonds with oxygen (no lone pairs), leading to \(sp^3\) hybridization. - \(\mathrm{H}_2\mathrm{S}\): Sulphur has two lone pairs and forms two bonds with hydrogen (total 4 electron domains), resulting in \(sp^3\) hybridization.

Step 3: Match Choices with Results

Based on our findings, \(\mathrm{SCl}_2\), \(\mathrm{SO}_4^{2-}\), and \(\mathrm{H}_2\mathrm{S}\) all exhibit \(sp^3\) hybridization. Therefore, the correct option is (b) 2, 3, and 4.

Key Concepts

Sulphur Compounds

Sulphur compounds are fascinating molecules that involve the element sulfur in combination with other elements, such as oxygen, hydrogen, and halogens. These compounds demonstrate a wide variety of chemical properties and bonding characteristics. Sulphur can form a range of compounds, from simple ones like hydrogen sulphide (\(\mathrm{H}_2\mathrm{S}\)) to more complex ions like sulphate (\(\mathrm{SO}_4^{2-}\)).

• **Hydrogen Sulphide (\(\mathrm{H}_2\mathrm{S}\))**: Sulphur forms bonds with two hydrogen atoms and has two lone pairs of electrons, making it a prime example of a simple sulphide compound.
• **Sulphate Ion (\(\mathrm{SO}_4^{2-}\))**: In this compound, sulfur is bonded to four oxygen atoms, leading to different bonding interactions due to its oxidation state and hybridization, specifically \(sp^3\).

Understanding sulphur compounds is essential to comprehending many biological and environmental processes, as sulfur is a key component in proteins and industrial chemicals.

Chemical Bonding

Chemical bonding lies at the heart of chemistry, providing insight into how atoms connect to form molecules. Sulphur, for example, can exhibit a variety of chemical bonds due to its ability to undergo different hybridizations.

• **Covalent Bonds**: Sulphur commonly forms covalent bonds where atoms share electrons. In \(\mathrm{SCl}_2\) and \(\mathrm{H}_2\mathrm{S}\), sulphur shares electrons with chlorine and hydrogen, respectively, resulting in polar covalent bonds due to electronegativity differences.
• **Coordinate Bonds**: In some compounds like sulphate ions, the bonding may also involve coordinate bonds, where one atom provides both electrons for a shared pair.

Chemical bonding influences the physical and chemical properties of sulphur compounds, such as boiling points, solubility, and reactivity, thereby playing a critical role in their behavior and use in different applications.

Electron Domains

The concept of electron domains is critical for understanding the geometry and hybridization of molecules. Electron domains include both bonded atoms and lone pairs around the central atom.In sulphur compounds:

• **Lone Pairs**: Substances like \(\mathrm{SCl}_2\) and \(\mathrm{H}_2\mathrm{S}\) feature lone pairs causing repulsion, shaping the molecule into a bent configuration.
• **Bonding Pairs**: Sulphur in \(\mathrm{SO}_4^{2-}\) forms four covalent bonds with oxygen, with no lone pairs disrupting the symmetrical tetrahedral shape.

Electron domains dictate the molecule's shape and the type of hybridization required to accommodate different arrangements. Understanding electron domains helps predict molecular geometry, thus informing reactivity and interaction with other chemicals.