Russian chemist Vladimir Markovnikov proposed Markovnikov’s rule in 1869 to predict the regiochemistry of addition reactions between unsymmetrical alkenes/ alkynes and hydrogen halides to form alkyl halides.
When two atoms come closer by attraction and overcome their repulsive interactions until they find a balance, at which point, the atoms’ contributes one valence electron each to form a stable, single covalent bond. So, the single covalent bond is a two-electron bond.
It is also known as the sigma bond and is denoted as a dash (-) between the two atoms.
Physical properties identify the substance's unique nature by subjecting the substance to qualitative and quantitative measurements. In these experiments, the substance does not undergo destruction or reconstitution of its composition but can undergo a change of states/phases.
An equimolar (1:1) mixture of a Lewis acid anhydrous ZnCl2 and concentrated HCl- Lucas Reagent, is used to identify and classify unknown alcohol (R-OH) as primary (1o), secondary (2o) or tertiary (3o). The Lucas test is based on the speed at which corresponding insoluble alkyl chlorides (R-Cl) are formed post reaction. The formation of alkyl chlorides solution appears as cloudiness/emulsion, and it is correlated with the reactivity of the alcohol, 3o alcohol being the most and 1o being the least.
A sp3 hybridized carbon is a tetravalent carbon that forms single covalent bonds (sigma bonds) with atoms of other p-block elements- Hydrogen, Oxygen, Carbon, Nitrogen, Halogens, etc. The bonds formed are of equal strength and at an angle of 109.5o due to which the central carbon atom is tetrahedral in shape. Example, carbon of an alkane or an alkyl group.
In Lewis Structures, the valence electrons are shown as dots. When atoms combine to form a bond, it is the electrons that participate. For Ionic Bonding there is a transfer of electrons (loss or gain), and for covalent bonding, the electrons are shared between the atoms. The atoms do so to attain the stable octet configuration of 8 electrons in their valence shell.
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.
The substances that on mixing with a suitable dispersion medium readily form a colloidal sol are called lyophilic (solvent loving) and the sols thus formed are known as the lyophilic sols.
Example, Gum, Starch, Gelatin, Rubber.
As the inherent tendency of these substances is to form colloids, they are also known as intrinsic colloids.
The process of transforming a freshly prepared precipitate to a colloidal sol by shaking it with a small amount of electrolyte having an ion common to the precipitate, in a dispersion medium is known as the peptization, and the electrolyte used for such a purpose is called the peptization agent.
Dialysis is a process of diffusion of the colloidal particles through a parchment or an animal membrane to remove excess of an electrolyte or any soluble impurities (crystalloids).
