Important Topic: Sulphide

Sulphide, often known as sulphide, is the inorganic anion of sulphur. Sulphide is essentially a chemical containing one or more S2 ions. Sulphide has the chemical formula S2 as well. Many metallic element sulphides are often found in nature as minerals. For example, pyrite is an iron sulphide with the formula FeS2. This is one of the most common sulphide minerals. Furthermore, mercury, copper, silver, zinc, cadmium, and many other elements are commonly found in nature as sulphides.

Sulphide Classifications

Sulphides are classified into three types: organic sulphides (also known as thioethers), inorganic sulphides, and phosphine sulphides.

• Sulfides of inorganic elements

Ionic compounds are common in inorganic sulphides. They include S₂, a negatively charged sulphide ion. In other words, these chemicals are essentially salts of extremely weak acid hydrogen sulphide.

• Sulfides of organic origin

The sulphur atom creates a covalent link with two organic groups. These sulphides are also known as thioethers.

• Sulfides of Phosphine

Phosphine sulphides are sulphides generated when organic phosphines combine with sulphur. The sulphur atom linked to phosphorus exhibits both ionic and covalent characteristics in this case.

Sulfide Structure

Molecular sulphides are those created from semimetals (metalloids) or certain nonmetallic elements. In a polymeric structure, they have sulphide bridges. Organic sulphide is an angular functional group, with the C–S–C angle nearing 90°. The C–S bonds are around 180 pm.

Properties of Sulphide

• Sulphide ion properties and chemical reactions do not exist in Na₂S aqueous alkaline solutions. Hydrosulfide is formed when sulphide is transformed to hydrosulfide.
• Sulphide salts react with acids to form hydrogen sulphide.
• The oxidation of sulphide is often a difficult process. It is mostly determined by the environment at the time of the reaction. As a result, depending on the circumstances, oxidation might produce elemental sulphur, polythionates, sulphite, polysulfides, or sulphate.
• Sulphur and metal salts are formed when metal sulphides react with halogens.
• Alkali metal and alkaline-earth metal sulphides are mildly soluble in water and appear to be predominantly ionic. The sulphides of copper and zinc are the least-soluble compounds.
• Sulphides are not very dangerous. Only a few metal sulphides create harmful hydrogen sulphide when exposed to strong mineral acids or stomach acids.
• Organic sulphides are extremely flammable. Sulphur dioxide (SO₂) gas is produced when sulphide is burned.
• Almost all organic sulphides have a strong, disagreeable odour. As an example, consider hydrogen sulphide and several of its salts.
• Many metals are susceptible to corrosion by dissolved free sulphides or sulphides present in aqueous solutions.

FAQs

Name some sulphide metal ores.

Pyrite (iron disulphide), galena (lead sulphide), argentite (silver sulphide), cinnabar (mercury sulphide), realgar (arsenic sulphide), pentlandite (nickel sulphide), sphalerite (zinc sulphide), and chalcopyrite (iron-copper sulphide) are a few examples.

Q. List of Sulphide Preparation Methods.

ANS: Sulfides can be manufactured in the following ways:

• When two elements combine directly, the result is Fe(s) + S(s) → FeS(s)
• By lowering the concentration of a sulphate: MgSO₄(s) + 4C(s) → MgS(s) + 4CO(g)
• Precipitation of an insoluble sulphide: M²⁺ + H₂S(g) → MS(s) + 2H⁺(aq)