Ionization vs Disassociation
Ionization and disassociation are two important topics discussed under chemistry of atoms and molecules. The concepts of ionization and disassociation play a vital role in fields such as chemical analysis, spectrometry, the characteristics of compounds, material science, radiation and radiation protection, and even in health and medical sciences. It is vital to have a proper understanding in the concepts of ionization and disassociation in order to excel in such fields. In this article, we are going to discuss what ionization and disassociation are, their definitions, the similarities of ionization and disassociation, applications of these two and finally the difference between ionization and disassociation.
Ionization is simply the process of creating an ion. This can occur in several ways. A molecule or an atom can become an ion by removing an electron, by adding an electron, removing an ion or adding an ion. The negative and positive charges of an ion are unbalanced. If the positive charges of an ion is greater than negative charges, the ion is a Cation. If negative charges are abundant than the positive charges, the ion is an Anion. Consider a neutral atom. To create a cation, the outer most electron must be removed from the atom. The energy required to take this electron from the orbital to infinity is known as the ionization energy. The first standard ionization energy is defined as the minimum energy required to remove the outermost electron completely from a gaseous atom in its ground state, measured under standard conditions. The opposite process of ionization is the electron affinity which adds electrons to the system. In the sense of the term, both ionization and electron affinity are ionizations, but they are defined differently for ease of calculation in thermodynamics.
Molecules are usually made up by combining two or more ions. Salt crystals consist of Sodium cations and Chlorine anions. When dissolved in water, the molecule disassociates to give original ions. Some crystals are made up from the crystallization of many molecules. Sugar is a good example for such a crystal. When such a crystal is dissolved in water, the molecules are released back. This is also disassociation. Removing an electron from a system cannot be considered as a disassociation. Disassociation is generally termed as breaking bonds between molecules or ions. When a salt is added to water, the salt totally disassociates until the solution is saturated. When a weak acid is added it will only partially disassociate crating equilibrium. Strong acids such as HCL will totally disassociate.
What is the difference between Ionization and Disassociation?
• Ionization always requires a removal or an addition of an ionic part to the compound, but disassociation does not require that.
• Ionization of a neutral molecule always yields two ions, which are opposite in sign and equal in magnitude, but disassociation of neutral compounds can create neutral molecules and ions alike.
• Ionization can be done by dividing or combining two or more compounds, but disassociation only occurs as a dividing method.
• Ionization can be either exothermic or endothermic, but disassociation is always endothermic.