Question

The oxidation number and covalency of sulphur in the sulphur molecule \(\left(\mathrm{S}_{8}\right)\) are respectively (1) 0 and 2 (2) \(+6\) and 8 (3) 0 and 8 (4) \(+6\) and 2

Short answer

Option (1) is correct: 0 and 2

Step-by-step solution

Define Oxidation Number

The oxidation number of an element in its molecular form (i.e., the form in which two or more atoms of the same element are bonded together) is always zero. Since we have the sulfur molecule \(\text{S}_8\), each sulfur atom will have an oxidation number of 0.

Define Covalency

Covalency is defined as the number of covalent bonds an atom can form. In the \(\text{S}_8\) molecule, each sulfur atom forms 2 covalent bonds with neighboring sulfur atoms to create a ring structure. Therefore, the covalency of sulfur in this molecule is 2.

Match Data to Provided Options

Given the oxidation number is 0 and the covalency is 2, review the provided options: (1) 0 and 2 (2) \(+6\) and 8 (3) 0 and 8 (4) \(+6\) and 2 The correct answer is (1), which matches our findings.

Key concepts

Oxidation Number

The oxidation number is a crucial concept in chemistry. It represents the degree of oxidation of an atom within a molecule. In simpler terms, it shows how many electrons an atom gains, loses, or shares when forming chemical bonds. For sulfur in its molecular form, such as in \(\text{S}_8\), the oxidation number is always zero. This is because it's just sulfur atoms bonded together, meaning no electron transfer happens. Hence, each sulfur atom in the \(\text{S}_8\) molecule has an oxidation number of 0.

Covalency

Covalency reveals how many covalent bonds an atom can form. Covalent bonds are formed when atoms share electrons to become more stable. For sulfur in \(\text{S}_8\), covalency is the number of bonds a sulfur atom can form with its neighbors. In the \(\text{S}_8\) structure, each sulfur atom forms 2 covalent bonds, creating a stable ring. Therefore, the covalency of sulfur in \(\text{S}_8\) is 2, as it forms exactly two bonds with other sulfur atoms.

Sulfur Molecules

Sulfur is a versatile element known for forming various molecular structures. One common structure is \(\text{S}_8\), where eight sulfur atoms bond together in a ring. Understanding sulfur's natural molecular structures helps to grasp its chemical behavior and reactions. In its \(\text{S}_8\) molecular form, sulfur is quite stable, which is why it’s commonly found in this form in nature. Other forms of sulfur molecules include \(\text{S}_2\) or polymeric chains under specific conditions.

Molecular Forms

Elements can exist in different molecular forms based on how their atoms are bonded. Sulfur, for instance, primarily exists as \(\text{S}_8\), a ring of eight atoms. These forms significantly determine the element's properties and uses. For sulfur, the \(\text{S}_8\) ring structure is responsible for its low reactivity under standard conditions. Understanding these forms helps you to predict and explain sulfur's physical and chemical properties, including its reaction mechanisms and uses in different industries.

Covalent Bonds

Covalent bonds are the glue that holds atoms together within a molecule. They form when atoms share pairs of electrons, aiming for full outer electron shells. In the \(\text{S}_8\) molecule, each sulfur atom shares electrons with two neighboring sulfur atoms, forming two covalent bonds. This sharing makes the molecule stable and defines its covalency as 2. Learning about covalent bonds is essential because they are fundamental to the structure and stability of many molecules, not just sulfur-based ones.