Distinguishing Double Salts and Coordination Compounds in Chemistry
When it comes to inorganic chemistry, the classification of compounds can be quite complex. Two of the most common types of molecular substances are double salts and coordination compounds. While both of these substances are made up of ions and have similar properties, they differ in their structure and composition. In this article, we will explore the differences between double salts and coordination compounds.
Double Salts
A double salt is defined as a compound that consists of two or more different salts, that are chemically bound together. Double salts form through the combination of two different salts, with the resulting substance having a unique chemical formula that differs from that of the individual components. For example, the double salt potassium aluminium sulfate, also known as alum, is a combination of potassium sulfate and aluminium sulfate. Double salts have distinct physical and chemical properties that differ from the parent salts.
Double salts are known for their crystalline nature and are characterized by their predictable stoichiometry, which is the ratio of the different ions present. The ions in double salts are not chemically bound to each other, but rather held together through ionic bonds. Double salts are used in various industrial applications, including water treatment and fertilizer production.
Coordination Compounds
Coordination compounds are a type of compound that contain a central metal ion bonded to a ligand group. They are characterized by the formation of coordinate covalent bonds, where electrons from the ligand are shared with the metal ion. Unlike double salts, coordination compounds have a fixed chemical composition, with the ligands being chemically bonded to the metal ion.
Coordination compounds are often colorful due to the presence of transition metals, which have partially filled d-orbitals that can absorb visible light. These compounds have a range of applications, including as catalysts and in medicinal chemistry.
The Key Differences
Overall, the main difference between double salts and coordination compounds lies in their composition and bonding. Double salts are composed of two or more different salts that are held together through ionic bonds, while coordination compounds are composed of a central metal ion that is surrounded by coordinated ligands. Furthermore, coordination compounds have a fixed chemical composition, while double salts have a varying stoichiometry.
In summary, distinguishing between double salts and coordination compounds is important in understanding their properties and applications in chemistry. By understanding their distinct characteristics, we can better appreciate the diversity of inorganic compounds and their role in our world.
Table difference between double salt and coordination compound
| Double Salt | Coordination Compound | |
|---|---|---|
| Type of Compound | A combination of two simple salts that crystallize together and can be separated by dissolving them | A complex compound in which a central metal ion is surrounded by ligands or neutral molecules |
| Bonding | Usually ionic bonding between two simple salts | Coordination bonding between central metal ion and surrounding ligands |
| Solubility | Generally less soluble compared to individual salts | Solubility depends on the nature of ligands and central metal ion |
| Physical Properties | Crystalline structures that can be easily broken down into simple salts | Complex structures with unique physical properties. |
| Examples | Potassium alum (KAl(SO4)2 . 12H2O) , Mohr’s salt (FeSO4 . (NH4)2SO4 . 6H2O) | Hexaamminecobalt(III) chloride ([Co(NH3)6]Cl3), Potassium tetracyanonickelate(II) ([Ni(CN)4]K2) |