The DBE calculation uses the general molecular formula to find the presence of unsaturation in a compound. The unsaturation is calculated in levels or degrees.
The lowest degree of unsaturation (DOU) indicates minimum unsaturation, where there is the least loss of hydrogens to form a pie bond or a cyclic ring, like in cycloalkanes.
General Molecular Formula
The redistribution of electrons in an atom, bond, or molecule creates two ends (or poles), one electron-rich negative and the other electron-deficient positive; such an atom, bond, or molecule is said to have a dipole (two poles).
The atoms or group of atoms are classified based on the Inductive effect as electron-withdrawing (-I) or electron-donating (+I) relative to Hydrogen.
The common functional groups showing +I and -I effect are:
+I group | -I group |
|---|---|
O- |
Polar molecules show Keesom forces. Polar molecules have heteroatoms that differ in electronegativity values such that the electronegativity difference between the two atoms in a polar covalent bond is greater than 0.5 but less than 1.7. For example, HF, HCl, R-OH, etc.
Learning Objective: To study the role of solvents in conformational isomerism.
Skill Level - Intermediate
Prerequisites:
Lone pair is a set of electrons present in an atom’s valence shell that did not participate in any bond-formation reaction. Since they refuse to bond with the other atoms, they are also called the non-bonding electrons. While drawing the molecules’ structure, the lone pair electrons on shown as dots (..) above the atom.
The peak on the Maxwell-Boltzmann energy distribution graph (fraction of molecules versus Kinetic energy) corresponds to the most probable kinetic energy, and it is the energy possessed by the maximum fraction of the reactant molecules at a temperature T.
Pre-Requisite Reading: Electronegativity
A covalent bond is formed between two similar or dissimilar atoms (Ex: Carbon-Carbon and Carbon-Halogen).
Few substances like gum, starch, gelatin, rubber have an inherent or a natural tendency to form colloidal sol on direct mixing with a suitable dispersion medium and are called intrinsic colloids. As they are solvent loving, they are also known as lyophilic colloids.
