General Introduction in IIT JEE Preparation

Important chapters in Physical Chemistry

Mole Concept: A mole is a unit of measurement used to measure the amount of any fundamental quantity such as atoms, molecules, ions that are present in any substance. A mole is very much similar to the weight, as it helps in understanding the amount of a substance present; it is defined as the amount of substance containing Avogadro’s number of atoms if the substance is atomic or we can also say that it contains Avogadro’s number of molecules if the substance is molecular, to illustrate for an example we can say that 1 mole of carbon atoms = 6.022 ×1023 atoms of carbon.

Structure of Atom: Atoms consist of three basic particles which are protons, electrons, and neutrons. The nucleus which is the centre of an atom contains the protons that are positively charged and the neutrons which have no charge and the outermost region of the atom is called electron shell and it contains electrons which are negatively charged. An atom is a complex arrangement of negatively charged electrons arranged in defined shells about a positively charged nucleus and this nucleus contains most of the atom’s mass and is composed of protons and neutrons.

Redox reactions: An oxidation-reduction (redox) reaction in which both oxidation reaction and reduction reaction takes place, to be more precise it is a type of chemical reaction that involves a transfer of electrons between two different species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

Important chapters for organic Chemistry

Name Reactions: The name reaction avoids the need to give an explanation of the features of a particular transformation of interest or the reaction. Mentioning the name reaction allows an individual to bring to mind the possible substrates, reaction conditions (basically the catalysts or the temperature and pressure), or the details about mechanism. Some of the examples include the Grignard reaction, the Sabatier reaction, the Wittig reaction, the Friedel-Crafts Acylation.

Organic Synthesis: Synthesis means breaking and it is the production of chemical compounds by reaction from simpler materials. Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. 

There are mainly five types of organic reactions:

• Substitution reaction.
• Elimination reaction.
• Addition reaction.
• Radical reactions.
• Oxidation-Reduction Reactions.

In an addition reaction the number of σ-bonds in the substrate molecule increases, usually at the expense of one or more π-bonds. Organic synthesis is the artificial construction of more complex organic molecules from simpler ones using chemical reactions.

Hydrocarbons: A hydrocarbon is made up of only the elements carbon (C) and hydrogen (H). The carbon atoms join together to form the skeleton of the compound, and the hydrogen atoms attach to them in many different configurations. 

Types of hydrocarbons:

1. Saturated Hydrocarbons. 
2. Unsaturated Hydrocarbons. 
3. Aromatic Hydrocarbons.
4. Aliphatic hydrocarbons. 

Aliphatic hydrocarbons are classified into three main groups according to types of bond, whether they are saturated or unsaturated and they are:

1. Alkanes.
2. Alkenes.
3. Alkynes.

Important chapters for Inorganic Chemistry

D-block elements: The d-block of the Periodic Table contains the elements of the group’s 3-12 in which the d-orbitals are progressively filled. There are mainly three series of the elements, 3d-series (Sc to Zn) 4d-series (Y to Cd) and 5d-series (La to Hg without Ce to Lu). The d-block metals, and some of its key alloys, shaped the Bronze Age, Iron Age, and most importantly the steel age. 

Properties of d-Block Elements

1. Metallic in nature.
2. Have high densities.
3. Have high melting and boiling point.
4. Form coloured ions and compounds.
5. The atomic radius decreases with increase in atomic number.

Coordination Compounds: In these compounds the central metal atom or ion is linked by ions or molecules with coordinate bonds. Coordination compounds are mainly formed because of the ability of ions and molecules to donate and accept electrons, leading to the formation of additional bonds between them and hence assuring of additional stability. One such example of a coordination compound is K4[Fe(CN)6]

Molecular Structure and Chemical Bonding: The attractive force which holds various constituents such as atoms, ions together in various chemical species is called a chemical bond. Atoms have a single nucleus with a positive charge surrounded by a cloud of negatively charged electrons and thus a molecule consists of atoms that come together by valence forces, on the other hand diatomic molecules contain two atoms that are chemically bonded.

General introduction and importance of biomolecules: 

Biomolecules are an organic molecule that includes carbohydrates, protein, lipids, and nucleic acids, which are important for the survival of living cells. There are four major classes of biological macromolecules which are carbohydrates, lipids, proteins, and nucleic acids and each is an important component of the cell and performs a wide array of functions, when combined, these molecules make up the majority of a cell’s mass. A biomolecule is a chemical compound found in living organisms. These include chemicals that are composed of mainly carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. Biomolecules are the building blocks of life and perform important functions in living organisms. 

Characteristics of Biomolecules

1. Most of them are organic.
2. They have specific shapes and dimensions.
3. The functional group determines their chemical properties.
4. Many of them are asymmetric.

Conclusion

Important chapters in Physical Chemistry Mole Concept Structure of Atom Redox reactions, states of matter whereas some of the essential topics for organic chemistry are Nomenclature, hydrocarbons, name reactions, organic synthesis and in case of inorganic chemistry we have d-block elements, coordination compound, chemical bonding