Bsc.CSIT Entrance Notes
Bsc-csitChemistry•Updated: 5/7/2026
CHEMISTRY NOTES
Chemistry helps understand materials and reactions relevant to scientific computation and technology.
PHYSICAL CHEMISTRY
1. MOLE CONCEPT, ATOMIC STRUCTURE, PERIODIC TABLE
Mole Concept
One mole contains Avogadro number of particles.
$$ 1\text{ mole}=6.022\times10^{23}\text{ particles} $$
Number of Moles
$$ \text{Moles}=\frac{\text{Given Mass}}{\text{Molar Mass}} $$
Atomic Number
Number of protons in nucleus.
$$ Z=\text{Number of Protons} $$
Mass Number
$$ A=\text{Protons}+\text{Neutrons} $$
Bohr Model
Electrons revolve around nucleus in fixed orbits.
Energy of Electron
$$ E_n=-\frac{13.6}{n^2}\text{ eV} $$
Periodic Table
Elements are arranged according to increasing atomic number.
Periodic Trends
Atomic Radius
Decreases across period and increases down group.
Ionization Energy
Increases across period.
Electronegativity
Ability to attract electrons.
2. CHEMICAL BONDING AND HYBRIDIZATION
Ionic Bond
Formed by transfer of electrons.
Example:
$$ NaCl $$
Covalent Bond
Formed by sharing electrons.
Example:
$$ H_2 $$
Coordinate Bond
Both electrons are donated by same atom.
Hybridization
Mixing of atomic orbitals.
Types of Hybridization
Hybridization | Geometry |
$sp$ | Linear |
$sp^2$ | Trigonal Planar |
$sp^3$ | Tetrahedral |
Bond Angle in Methane
$$ 109.5^\circ $$
3. CHEMICAL & IONIC EQUILIBRIUM, THERMODYNAMICS, KINETICS
Chemical Equilibrium
At equilibrium:
$$ \text{Rate of Forward Reaction} = \text{Rate of Backward Reaction} $$
Equilibrium Constant
$$ K_c=\frac{[C]^c[D]^d}{[A]^a[B]^b} $$
Ionic Product of Water
$$ K_w=[H^+][OH^-] $$
pH Formula
$$ pH=-\log[H^+] $$
First Law of Thermodynamics
$$ \Delta U=q+w $$
Enthalpy Change
$$ \Delta H=H_{products}-H_{reactants} $$
Gibbs Free Energy
$$ \Delta G=\Delta H-T\Delta S $$
Rate Law
$$ \text{Rate}=k[A]^m[B]^n $$
Arrhenius Equation
$$ k=Ae^{-E_a/RT} $$
4. OXIDATION-REDUCTION, ELECTROCHEMISTRY, STATE OF MATTER
Oxidation
Loss of electrons.
Reduction
Gain of electrons.
Oxidation Number
Represents apparent charge on atom.
Electrochemical Cell
Converts chemical energy into electrical energy.
Nernst Equation
$$ E=E^\circ-\frac{0.0591}{n}\log Q $$
Ideal Gas Equation
$$ PV=nRT $$
Boyle's Law
$$ PV=\text{constant} $$
Charles's Law
$$ \frac{V}{T}=\text{constant} $$
INORGANIC CHEMISTRY
5. WATER, NITROGEN, OXYGEN FAMILY
Properties of Water
Universal solvent with high specific heat.
Hard Water
Contains dissolved calcium and magnesium salts.
Ammonia
$$ NH_3 $$
Colorless gas with pungent smell.
Nitric Acid
$$ HNO_3 $$
Strong acid and oxidizing agent.
Oxygen
Supports combustion and respiration.
Ozone
$$ O_3 $$
Protects earth from ultraviolet rays.
6. SODIUM, METALLURGY, HEAVY METALS, HALOGENS
Sodium
Highly reactive alkali metal.
Sodium Hydroxide
$$ NaOH $$
Used in soap industry.
Metallurgy
Extraction of metals from ores.
Heavy Metals
Examples include:
$$ Pb, Hg, Cd $$
Halogens
Group 17 elements.
Chlorine
$$ Cl_2 $$
Used in water purification.
ORGANIC CHEMISTRY
7. SOURCES AND PURIFICATION OF ORGANIC COMPOUNDS
Sources of Organic Compounds
- Plants
- Animals
- Petroleum
- Coal
Distillation
Method used for purification.
Crystallization
Purification using difference in solubility.
Sublimation
Solid directly converts to gas.
8. NOMENCLATURE, FUNCTIONAL GROUPS, ISOMERISM
IUPAC Nomenclature
Standard naming system for organic compounds.
Functional Group
Atom or group determining properties.
Functional Group | Formula |
Alcohol | $-OH$ |
Aldehyde | $-CHO$ |
Ketone | $>C=O$ |
Carboxylic Acid | $-COOH$ |
Amine | $-NH_2$ |
Isomerism
Compounds with same molecular formula but different structures.
Types of Isomerism
- Structural Isomerism
- Geometrical Isomerism
- Optical Isomerism
9. HYDROCARBONS, ALCOHOLS, PHENOLS, ETHERS, ALDEHYDES, KETONES, CARBOXYLIC ACIDS
Hydrocarbons
Compounds containing carbon and hydrogen.
Alkane
General formula:
$$ C_nH_{2n+2} $$
Alkene
General formula:
$$ C_nH_{2n} $$
Alkyne
General formula:
$$ C_nH_{2n-2} $$
Alcohol
Contains hydroxyl group.
Example:
$$ C_2H_5OH $$
Phenol
Aromatic compound containing hydroxyl group.
Ether
General formula:
$$ R-O-R' $$
Aldehyde
Contains:
$$ -CHO $$
Ketone
Contains:
$$
C=O $$
Carboxylic Acid
Contains:
$$ -COOH $$
Esterification Reaction
$$ \text{Alcohol} + \text{Acid} \rightarrow \text{Ester} + H_2O $$
10. AMINES, NITRO COMPOUNDS, MOLECULES OF LIFE
Amines
Organic derivatives of ammonia.
Primary Amine
$$ R-NH_2 $$
Nitro Compound
Contains:
$$ -NO_2 $$
Biomolecules
Carbohydrates
Source of energy.
Example:
$$ C_6H_{12}O_6 $$
Proteins
Made of amino acids.
Lipids
Store energy and form cell membrane.
DNA
Carries genetic information.
IMPORTANT FORMULAS SUMMARY
Mole Formula
$$ \text{Moles}=\frac{\text{Mass}}{\text{Molar Mass}} $$
Ideal Gas Equation
$$ PV=nRT $$
Gibbs Free Energy
$$ \Delta G=\Delta H-T\Delta S $$
pH Formula
$$ pH=-\log[H^+] $$
Nernst Equation
$$ E=E^\circ-\frac{0.0591}{n}\log Q $$
Arrhenius Equation
$$ k=Ae^{-E_a/RT} $$