Revision - chemistry for jee mains


Chemistry Formulas

  • Matter is substance which has mass and occupies space, e.g., water, air, box, table, etc.
  • State of Matter: Solid, liquid and gaseous state represent three different states of mater. Gaseous mater at very high temperatures contains gaseous ions and free electron and is referred to as the plasma state, i.e., fourth state of matter.
  • Homogenous: These have uniform. composition throughout, e.g., elements and compounds. Mixture can also be homogeneous.
  • Heterogeneous: These do not have uniform Entrance composition, e.g., mixture of iron fillings and sulphur powder.
  • Element: It is a substance which cannot be further divided by chemical methods. It is a pure substance and consists of only one kind of atoms. They are metals, non-metals and metalloids (resemble both metal and non metal), e.g., F, Al, Ni, Au, Ag are metals. C, S, N2, I2 are non-metals. B. Si, As, Sb are metalloids. They are pure substances.
  • Compound. It is a pure substance made up of two or more elements combined together in fixed ratio, e.g., NaCl, FeS, CuSO4, H2O, etc. Its components cannot be separated by simple physical methods.
  1. Organic compounds: They are compounds containing carbon and few other elements like H, N, S, halogens, phosphorus, oxygen etc. e.g., sugar, urea, glucose, etc.
  2. Inorganic compounds: They are made up of two or more elements and obtained form minerals and ores, e.g., NaCl, KCl, CaCO3, etc.
  • Mixture: It consists of two or more elements or compounds in any ratio. Its components can be separated by simple physical methods. It can be homogeneous (e.g., solution of salt in water, sugar in water). It can be heterogeneous. e.g., smoke dust particles in air, air, etc. Homogeneous mixture is also called solution.
  • Separation of Mixtures: Mixtures are separated into its components depending upon the property of components in which they differ.
  1. Filtration: It is used to separate suspended (insoluble) component from a soluble component which passes into the filtrate and the insoluble component is left behind on the filter paper. Soluble component can be obtained by evaporation.
  2. Simple Distillation: It is used for separation of miscible liquids which differ in their boiling points appreciably, e.g., benzene and toluene can be separated by simple distillation.
  3. Fractional Distillation: It is used for separation of miscible liquids which differ in their boiling points appreciably, e.g., benzene and toluene can be separated by simple distillation.
  • Molecules: They are identifiable units of matter consisting of two or more atoms of the same element or of different elements combined in a definite ratio.
  • Atomicity: It is defined as the number of atoms present in a molecule.
  • Monoatomic: They consist of only one atom, e.g., He, Ne, Ar, Kr, Xe, Na, K, etc.
  • Diatomic: They consist of two atoms, e.g., H2, Br2, Cl2, F2, I2, N2, O2, HCl, HBr, etc.
  • Triatomic: They consist of three atoms, e.g., O3, H2O, SO2, CO2 etc.
  • Tetra-atomic: They consist of four atoms, e.g., P4, SO3, NH3 etc.
  • Penta-atomic: It contains five atoms, e.g., CH4, CCl4, SiCl4 etc.
  • Hexa-atomic: It contains six atoms, e.g., C2H4, H2SO3.
  • Hepta-atomic: It contains seven atoms, e.g., H2SO4.
  • Octa-atomic: It contains eight atoms, e.g., S8 is octa-atomic molecule.

Mole Concept

A mole is the amount of a substance that contains as many atoms, molecules, ions or other particles as there are atoms in 0.012 kg (or 12g) of the carbon-12 isotope. The mole of a substance always contains same number of particles, whatever the substance may be.

Laws of Chemical Combinations

  • Law of Conservation of Mass (discovered by Lavosier): Matter can neither be created nor be destroyed. The total mass of reactants must be equal to total mass of products. For example C + 02 → CO2

12g + 32g = 44g

That is why we balance each and every chemical reaction.

  • Law of Constant Composition (discovered by Proust): A compound prepared by any method contains the same elements in the fixed ratio by mass, e.g., H2O prepared by any method contains hydrogen and oxygen in the fixed ratio 1 : 8 by mass.
  • Law of Multiple Proportion (discovered by Dalton): When two elements combine to form two or more chemical compounds, then the weights of one of the elements which combine with the fixed weight of another, bear a simple ratio to one another, e.g., carbon reacts with oxygen to form carbon monoxide and carbon dioxide.

In CO, 12 parts by weight of carbon combine with 16 parts by weight of oxygen.

In CO2, 12 parts by weight of carbon combine with 32 parts by weight of oxygen.

The ratio between different weights of oxygen that combine with 12 parts (fixed weight) of carbon is 16 : 32, i.e., 1 : 2

Law of Reciprocal Proportion (discovered by Richter)

  • When two elements combine separately with a fixed mass of third element, then the ratio of their masses in which they combine will be either same or simple multiple of the ratio in which they combine with each other, e.g., C and O2 react with S to form CS2 and SO2 whereas carbon reacts with O2 to form CO2
  • 32 parts by weight of S combine with 32 parts by weight of oxygen in SO2
  • 32 parts by weight of S combine with 6 parts by weight of carbon in CS2.
  • The ratio 6 : 32 which is multiple of 12 : 32 in CO2.


Thomson Model of Atom

  • J.J. Thomson proposed a model in which atom was assumed to be uniform sphere with radius 10 cm of positive electricity (positive charge) with electrons embedded into it in such a way as to give the most stable electrostatic arrangement.

positive charge

  • In this model the atom is visualized as a pudding or cake of positive charge with raisins (electrons) embedded into it. This model is also called the ‘raising pudding’ model.

Drawback of Thomson Model of Atom

This model of atom could account for the electrical neutrality of atom, but it could not explain the results of gold foil experiment carried out by Rutherford.


They are positively charged (+2) helium ions having high energy emitted during radio-active decay of unstable elements like Uranium. It has +2 charge and mass 4u.

Rutherford’s a-Scattering Experiment (Discovery of Nucleus)

Rutherford bombarded high energy a-particles from radioactive source on thin foil (thickness 10–7m) of gold metal. The thin gold foil had a circular flurescent ZnS screen around it. Whenever an a-particle struck the screen, a tiny flash of light was produced at that point. He observed that :

deflected ray

  1. Most of a -particles passed through the gold foil undeflected.
  2. A small fraction of a-particles was deflected by small angles.
  3. A very few a-particles (1 in 2000) bounded back, i.e., were deflected by nearly 180°.

Rutherford’s Conclusions regarding Model of Atom:

  • Most of space in atom is empty because most of a-particles passed through the foil.
  • The positive charge has to be concentrated in a very small volume that repelled and deflected few positively charged a-particles. This very small portion of the atom was called nucleus.
  • The volume of nucleus is very small as compared to total volume of atom. The radius of nucleus (10–13 cm) is about 1/100,000 of that atom (10–8 cm). If cricket ball is nucleus then radius of atom will be about 5 km.
  • The volume of nucleus is very small as compared to total volume of atom. The radius of nucleus (10–13 cm) is about 1/100,000 of that atom (10–8 cm). If cricket ball is nucleus then radius of atom will be about 5 km.

Rutherford’s Nuclear Model of Atom:

  1. An atom consists of tiny positively charged centre called nucleus.
  2. The nucleus consists of protons and neutrons called nucleons.
  3. Nucleons (proton and neutron) are much heavier than an electron indicating that mass of atomlies in its nucleus. The total number of nucleons is termed as mass number.
  4. The electrons are outside the nucleus revolving around nucleus at high speed in certain fixed circular path called orbits in the same manner as planets move around sun.


The restriction of a property to discrete values and not continuous values is called quantization.

Hydrogen Spectrum

If a discharge is passed through hydrogen gas at a low pressure, some hydrogen, atoms are formed, which emit light in the visible region. This can be studied by using Spectroscope or Spectrometer, and is found to comprise of series of lines of different wavelength. The four lines can be seen by eyes, but many more observed photographically in ultraviolet region.

Quantum Numbers

Atomic orbitals can be specified by giving their corresponding energies and angular momenta which are quantised (i.e., they can bave some specific values). The quantised values can be expressed in terms of quantum number. They are used to get complete information about electron. i.e., location, energy, spin, etc.

Principal Quantum Number

It specifies the location and energy of an electron. It is the measure of the effectiv volume of the electron cloud. It is denoted by `n’. Its possible values are 1, 2, 3, … for K, L, M, N…

Pauli Exclusion Principle

No two electrons in an atom can have the same four quantum numbers. It can also be stated as—An orbital can bave maximumtwo electrons and they must be of opposite spin quantum numbers.


Chemistry Formulas

Class 11 Chapter- Gaseous State

Units :

  • St unit for volume is cubic metre (m3).
  • St unit for mass is kilogram.
  • St unit for pressure is Pascal (1Pa = 1N/m2).
  • 1 poise = 1 g cm–1s–1 = 10–1 kg m–1 s–1
  • Viscocity Units (SI) = N sm–2 or Pas.
  • 1 kg is defined as the mass of a certain block of platinum-Iridium alloy preserved at Sevres out side Pairs.
  • 1 atm = 76 cm of Hg = 760mm of Hg = 1.01325 × 105 N/m2
  • 1 m2 Column of air extending from the earth’s surface through the upper at me sphere has a mass of about 10.300 kg. It exerts pressure 101kPa.
  • T = t°C + 273 (Absolute temperature/Kelvin temperature/Thermodynamic temperature)
  • S.T.P conditions

Latest Value (at Sea Level)

Standard temperature at STP = 273.15K

Standard pressure at STP = 105Pa

Molar volume at STP = 22.71 L

Earlier Values

Standard temperature at STP = 273.15K

Standard pressure at STP = 760 mm or 101.325 kPa.

Molar volume at STP = 22.414L

  • Number of molecules in one mole og gas is 6.022 × 1023, which is also known as Avogadro’s number (NA)

Boyle’s Law

“The volume of a given mass of a gas at constant temperature is inversely proportional to the pressure” P1V1 = P2V2.

  • Graphs between P & V at constant temperature are called “Isotherms”

Charles Law

“At constant pressure, the volume of a given mass of a gas at 0°C, increases or decreases by 1/273 times its volume for every degree rise or fall in temperature respectively”.

  • According to Charless-Gaylussac law volume at t°C is Vt = V0

charles law

Dalton’s Law

  • According to Dalton’s law of partial pressures, “the totalpressure exerted bya mixture ofnon- reaching gases is the sumof the individualpres- sures that each gas would exert if it were present alone in the container at the same tem- perature”.
  • PTotal = PA + PB+ PC + …
  • Mole fraction of gas = number of moles of one gas total number of moles in mixture
  • Pressure of dry gas = observed pressure - aqueous tension.

Kinetic Molecular Theory Of Gases

  • Gases contain large number of tiny and dis- crete particles called molecules.
  • The molecules move randomly in all the di-rection with high velocities.
  • The volume of the molecule is negligible com- pared to the volume of the container or the mean free path is very high compared to the diameter of the molecule.
  • Molecules are electrically neutral and do not have attractions or repulsions between them.
  • The molecular collisions are perfectly elastic.
  • Molecular motions are uneffected by gravity.
  • Pressure exerted by a gas is due to the colli- sions of molecules made on the walls of the vessel. There is no loss of energy in these collisions.
  • Average Kinetic Energy αT

Liquefaction of Gases

  • Intermolecular forces are inversely propor- tional to thermal energy.
  • If thermal energy predominates, solid→liquid→ gas
  • If intermolecular forces predominates, gas→liquid→solid
  • Critical temperature (TC) is the temperature at which the gaseous state transforms continuously into the condensed state or liquid state.
  • Pressure required to liquefy a gas at it’s critical temperature (TC) is called critical pressure (TC)
  • Volume occupied by one mole of the gas at critical temperature and critical pressure is critical volume (TC).
  • Critical temp of CO2 = 31.040 C (304.19K).

Conditions of liquefaction of gases

  • A gas liquefies if it is cooled below its boiling point at given pressure. For example: Chlorine at liquefied by cooling it to -34.00C in a dry ice bath.
  • For N2 and O2 that have very low boiling points -1960C and -1830C, such simple technique is not suitable. Then to liquifity such type ofgases technique based on itermolecular forces is used.
  • For this the velocities of moleculesare reduced to such lower values that neighbors can at- tract each other by their interaction or inter molecular attractions, then the cooled gas will condense to a liquid.
  • The molecules are allowed to expand into available volume during which the molecules overcome inter moleculear attractions by using their kinetic energies.
  • The way of cooling of gas by expansion from high pressure side to low pressure is called joule-Thomson effect.


Chemistry Formulas

General characteristics of Equilibrium Involving Physical Processes:

  • For liquid 3/4,33,3/44 vapor equilibrium, the vapor pressure is constant at a given temperature.
  • For solid 3/4,33,3/44 liquid equilibrium, there is only one temperature, i.e., (melting point) at a melting point at which solid and liquid co-exist. If there is an isolated system, the mass of the two phases remains constant.
  • The solubility of solids in liquid is constant at a particular temperature.
  • For the dissolution of gases in liquids, the concentration of a gas in a liquid is proportional to the pressure (concentration) of the gas over the liquid.
  • Equilibrium is possible only in a closed system at a given temperature.
  • There is dynamic equilibrium but stable condition.
  • All measurable properties of the system remain constant at equilibrium.
  • The magnitude of such quantities at any stage indicates the extent to which the reaction has proceeded.

For the given general equation Kc & Kp

xA + yB⇄ mC + nD

equilibrium constant

where KC = equilibrium constant interms of concentration

partial pressure

Where KP = equilibrium constant interms of partial pressure

  • Relation between KC & KP

Kp = Kc(RT)Δn

where Δn no. of moles of gaseous products-. No. of moles of gaseous reactants.

R = gas constant

T = Temperature in Kelvin

no. of moles

  • Equilibrium constant = KC

forward reaction

  • The expression for KC & KP for the equations


But [CaCO3], [CaO] are taken as unity

Since CaCO3, CaO are solids

KC = [CO2]

Equilibrim Formula

This approach comes from kinetics, as developed by Guldberg and Waage (1863). Equilibrium is known to have reached in a physical or chemical system when the rate of forwarding and reverse processes are equal.

At equilibrium,

Rate of forwarding reaction = Rate of backward reaction

Law of Chemical Equilibrium

rf = rb



Chemistry Formulas

Class 11 chapter- Periodic Table

Doebereiner’s Law of Triads

He arranged the elements in group of three such that atomic weight of middle element is average of first and third element. These elements resembled in their properties.

Element Atomic weight
Li 7
Na 23
K 39
Ca 40
Sr 88
Ba 137
Cl 35.5
Br 80
I 127


He could not classify all the elements discovered at the time into Iriads.

Newland Law of Octaves

He arranged the elements in increasing order of their atomic weights and that any given element has similar properties to the eight element that followed it. The relationship was same as that existing between musical note and its octave.

Li Be B C N O F
Na Mg Al Si P S Q
K Ca


He could not classify all the elements discovered at that time.

Mendeleev’s Periodic law

“The properties of the elements, as well as the formulae and properties of their compounds depend in periodic manner on the atomic weight of the elements”.

Modern Periodic Law

“The properties of elements, as well as the formulae and properties of their compounds are periodic functions of atomic number of the elements”.

Representative Elements

The elements of group! (alkali metals), group 2 (alkaline earth metals) and group 13 to 17 constitute the representative elements. They are elements of s-block and p-block.

Transition Elements

These are the elements of group 3 to 12 in the centre of the periodic table. They also called d-block elements. They have general electronic configuration (n-i) d1–10 ns0–2. They are metals. They show variable oxidation state and form coloured ions.

Inner-Transition Elements

Lanthanoids (the fourteen elements after Lanthanum) and actinides (the fourteen elements after actinium) are called inner transition elements. Their general electronic configuration is (n – 2) t0–14 (n – 1)d0–2 ns2. They are also called f-block elements. They are all metals. They show variable oxidation states. Their properties are quite similar.

Ionization Enthalpy

It is the energy required to remove an electron from an isolated gaseous atom in its ground state.


Screening Effect

The reduction in force of attraction by the electrons of shells present in between nucleus and valence electrons is called screening effect or shielding effect. Greater the number of intervening electrons between valence electron and nucleus, the greater will be shielding or screeding effect.


Chemistry Formulas

" Thermodynamics" is the sixth chapter of the NCERT Class 11 Chemistry textbook. Thermodynamics is a branch of science that deals with the relationship between heat and other forms of energy. The part of the universe in which the observation is called is a system. The system environment is part of the universe that does not contain a system. Based on the exchange of energy and matter, thermodynamic systems can be divided into three types: closed system, open system, an isolated system.

In a closed system, only energy can be exchanged with the environment. In an open system, power and matter can be exchanged around. In an isolated system, energy and matter cannot be exchanged with the environment.

Thermodynamics formula

  • Universe = system + surrounding
  • W = F x dx

Where, W = Work Done

F = Force

Dx= distance moved


  • Work done by a system = –ve
  • Work done on the system = +ve
  • C=q/dT**;** q = Heat absorbed, dT = rise in temperature.
  • Q = ΔE+W…………I (law of thermodynamics)
  • q = dE + W ………… I l(aw of thermodynamics)
  • Heat absorbed by a system = +ve
  • Heat given out by a system = –ve
  • H = E + PV
  • CP – CV = R, R = Gas constant, CP = Heat capacity at constant pressure
  • thermodynamics
  • Molar heat capacity = specific heat x molecular weight.
  • Heat liberating reactions are exothermic reaction, ΔH= –ve
  • Heat absorbing reactions are endothermic reaction. ΔH = +ve
  • Heat of combustion = Z x θ x M/n, M = molecular weight, m = weight of substance

θ= rise in temperature

Z = heat capacity

  • Heat liberated = (W + volume of reaction mixture) x rise in temperature

heat liberated

m1 = mass of water at lower temperature

m2 = mass of water at higher temperature

t01C = Lower temperature

t02C = higher temperature

t03C = resultant temperature

W = water equivalent of calorimeter + stirrer


Chemistry Formulas

Class 11 chapter- S-Block Elements

  • Oxides of Li, Na, K, Rb and Cs dissolve in water to give strong alkalies. So tehse elements are known as alkali metals.
  • Among alkali metal Fr is a liquid radioactive element.
  • The lightest alkali metal is lithium.
  • Except Lithium, all other alkali metals are stored in kerosene.
  • The lowest I.P. value element among alkali metal is Cs.
  • The alkali metals used in photo electric cells are Cs and K.
  • The common oxidation state of alkali metals is +1.
  • The density of K is less than Na due to the presence of vacant 3d orbitals and greater inter atomic distance in the crystal lattice.
  • Alkali metals are highly reactive. The reactivity increases from Li to Cs.
  • The super oxide ion contains unpaired electron, so alkali metal super oxides are paramagnetic.
  • Alkali metal oxides react with water giving their hydroxides. The solubility in water increases from LiOH to CsOH.
  • Alakali metals react with H2 to give hydrides. These hydrides are ionic in nature.
  • Thermal stability of the hydrides decreases with increase in ionic nature.

Preparation of sodium hydroxide

  1. Causticizing process
  2. Electrolytic process

sodium hydroxide

Nelson Cell process

  1. Electrylyte : Brine solution (aq. NaCl)
  2. Cathode : Perforate U-shaped iron tank lined inside with asbestos
  3. Anode : Graphite rod
  4. At cathode :

cathode reaction

  • At anode : 2Cl– →Cl2 + 2e–

Castner-Kellner process:

  • In outer compartment – Electrolyte – Brine Solution
  • Anode-Graphite Cathode – Hg
  • Middle compartment – Electrolyte – dilute NaOH
  • Anode – Hg Cathode – Iron rods

Reaction with metals :

reaction with metal

Reaction with non-metals

reaction with nonmetal


Chemistry Formulas

Class 11 chapter- Redox Reactions

  • The chemical reaction which contain oxidation as well as reductuib half reaction is called redox reaction.
  • An atom or ion or molecule which undergoes reduction (gain of electrons) is called oxidant (while an atom or molecule) which undergoes oxidation) (loss of electrons) is called reductant.
  • Oxygen shows positive oxidation states (+1 and 2) only in OF2 and O2F2.
  • Maximum oxidation state of an element never more than its group number.
  1. Oxidation state of Mn in KMnO4 is +7.
  2. Oxidation state of Cr in K2Cr2O7 is +6.
  3. Oxidation sate of Cr in CrO5 is +6.
  4. Oxidation state of ‘N’ in N3H is –1/3.
  5. Oxidation state of ‘N’ in NH4NO3(NH4+ and NO3–) are –3 and +5.
  6. Oxidation state of ‘Fe’ in FeSO4 is +2.
  7. Oxidation state of ‘Fe’ in Fe3O4 is +8/3.
  • In xMnO4– + yH2O + zI–→2MnO4- +8OH-+3l2

x = 2, y = 4, z = 6

  • CH4 + 2O2 →CO2 + 2H2O is an example for chemical combustion.
  • In all combustion reactions oxygen undergoes reduction (0 to –2).
  • In decomposition reaction chemical compound split into two or more simpler substances.


  • In decomposition of MgCO3, no changes in oxidation numbers. So it is not a redox reaction

[MgCO3 →MgO + CO2]

  • Zn(s) + CuSO4(aq) →ZnSO4(aq) + Cu(s) is a displacement reaction.
  • In disproportionation reaction the same element undergoes both oxidation and reduction simultaneously.
  • When Br2 and I2 dissolve in CCl4 solvent to give reddish brown and purple colours respectively. So, they are detected by extracting into CCl4. This is also called “Layer Test”.
  • Comproportion is a reverse of disproportionation reaction. Ag2+(aq)+Ag(s)→2Ag+(s) is a comproportionation reaction.


Chemistry Formulas

Class 11 chapter- P-Block Elements

  • Boron, Aluminium, Gallium, Indium and Thalium belong to IIIA group of the periodic table.
  • B and Al show similar properties due to similar outer E.C.
  • Atomic radius increases suddenly from B to Al. This is due to the greater screening effect of electron present in the (n – 1) shell.
  • The atomic radii of Al is greater than Ga. This is because of the poor shielding effect of d-electron of Gallium.
  • Gallium exists as liquid between 29.8°C and 2000°C.
  • The low melting point of Ga is due to its simple molecular structure. It consists of Ga2 molecules.
  • The most electro positive element in IIIA group is Al.
  • Boron exhibits –3 and +3 oxidation states.
  • Due to inert pair effect +1 oxidation state of Thalium is more stable.
  • The Trihalides of B and Al are covalent, electron deficient and can act as Lewis acids.
  • 95 – 98% pure Boron is obtained on reducing B2O3 with Mg or Na metal at high temp. It is known as Moissan Boron.
  • Boron is non-conductor of electricity.
  • Boron in non-conductor of electricity.
  • Boron carbide is the hardest compound of Boron. Its formula is B4C3.
  • Borax is Na2B4O7.10H2O (Tincal).
  • Borax is available in nature as Kernite (Na2B4O7.4H2O) (Rasorite)
  • Borax bead test : On heating borax it swells into a white, opaque mass of anhydrous sodium tetra borate. When it is fused, borax glass (NaBO2 + B2O3) is obtained.
  • The hydrides of Boron are called boranes.
  • These are electron deficient molecules.
  • The general formula of boranes
  1. BnHn+4
  2. BnHn+6
  • Diborane (B2H6) is an electron deficient molecule
  • Preparation of diborane :

preparation of dibrone

  • Properties of diborance :

preparation of dibroce

  • The hybridization of Boron in diborane is Sp3.
  • In B2H6, the four hydrogen atoms lie in one plane are called terminal hydrogen atoms and the remaining two hydrogen atoms are called bridge hydrogen atoms.
  • The bridge hydrogen atoms are involved in three centered two electron bond called banana bond (or) Tau bond.


Chemistry Formulas

Class 11 chapter- Hydrogen

  • Isotopes of hydrogen are protium (21H); Deuterium (21H) or (21D) and tritium (31H) or (31T).
  • 31T (Tritium) is radioactive and has a half life period of 12.26 years.
  • A mixture of CO and H2 is known as water gas. It is also called as synthesis gas (or) syn gas.
  • Coal gas contains hydrogen (45 – 55%) ; methane (25 – 35%) and carbon monoxide (4 – 11%).
  • Its calorific value is 21,000 Kjm–3
  • The composition of water gas is carbon monoxide (40 – 50%); hydrogen (45 – 50%) and small amounts of CO2 and N2. Its calorific value is 13,000 KJm–3.
  • Semi water gas composition is H2 (10 – 20%), CO (25 – 28%), CO2 (4 – 5)%, N2 (50 – 55%) and CH4 (1 – 12%). Its calorific value is 7524 KJm–3.
  • Fuel cells- Electro chemical cells in which chemical energy released in a combustion reaction is converted into electrical energy.
  • The temporary hardness of water is due to the presence of bicarbonates of calcium and magnesium.
  • The permanent hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium.
  • Permanent hardness of water is removed by
  1. Permutit process
  2. Calgon process
  3. Ion exchange method.
  • Permutit is artificial Zeolite, Zeolite is hydrated sodium aluminium orthosilicate (Na2Al2Si2O8, nH2O)
  • Exhausted permut it can be regenerated by washing it with 10% aqueous brine solution.
  • Calgon is sodium hexa meta phosphate. Na2[Na4(PO3)6] (or) (NaPO3)6
  • The number of parts by weight of calcium carbonate present in million parts by weight of water is known as the degree of hardness of water.
  • The degree of hardness of water is expressed in terms of ppm oc CaCO3
  • D2O is heavy water. I part in 6000 parts of ordinary water.
  • H2O2 is also known as oxygenated water.
  • 30% (w/v) aqueous solution of hydrogen peroxide is known as perhydrol.
  • H2O2 is prepared by electrolysis of 50%. H2SO4. At cathode H2 and at anode H2S2O8.

H2S2O8 + 2H2O →2H2SO4 + H2O2.k


Chemistry Formulas

Class 12 chapter- Alkyl and aryl halide

  • Haloalkanes (Alkayl halides): The are halogen derivatives of alkanes. They have general formula ‘CnH2n=1X’, where ‘X’ is F, Cl, Br or I, e.g., methyl chloride (CH3Cl), ethylbromide (C2H5Br), Etc.
  • Haloarenes (Aryl halides): The halogen atom in these halides is directly linked to an aromatic ring carbon e.g.,


These are also called haloarenes. Thus, benzylic and aryl halides are special types of haloarenes.

  • Peroxide effect or Kharasch effect: When a polar compound is added to unsymmetrical alkenes or alkynes in presence of organic peroxides, e.g., benzoyl peroxide, the negative part of addendum goes to that carbon atom which is maximum substituted, e.g., CH3 – CH

aryls arylt

  • Elimination reaction: Alkyl halides undergoe -elimination of hydrogen and halogen atom to form alkenes on being heated with KOH (alc.) or KNH2, e.g…

elimination reaction

The reaction is called dehydrohalo genation. The following is order of reactivity: RCl < RBr < RI


  • Saytzeff rule: In most of elimination reaction, more alkylated (alkyl substituted) alkene is the major product. The stability of more alkylated alkene is due to its lower energy. Hyperconjugation effect of alkyl group helps in lowering the energy of the product e.g…

saytzeff rule

  • Reactivity of SN1 and SN2 mechanisms: S = substitution, N = Nuclephilic, 2 = Bimolecular, 1 = Unimolecular, Nuclephilic substitution seldom occurs exclusively by one mechanism only. With a given halogen, primary, secondary and tertiary halides show opposite order of reactivity in the two mechanisms.


Chemistry Formulas

Class 12 chapter- Alcohol phenol and ether

  • Alcohols: When one hydrogen atom of alkene is replaced by –OH group, the compounds obtained are called ‘Alcohols’ having general formula ‘CnH2n+1OH’. They are also called monohydric alcohols because they contain one –OH group, e.g., CH3OH (Methanol), C2H5OH (Ethanol), etc.
  • Electrophile: It is positively charged or neutral species which is electron deficient, e.g… NH4+, BF3, AlCl3, SO3, FeCl3 etc
  • Nucleophile: It is negatively charged or neutral species with lone pair of electrons. E.g.,


  • Salicylic acid (2-hydroxybenzoic acid): It is formed by the reaction of sodium phenoxide with CO2 under pressure at 400 K followed by acidification of product. It is used to prepare aspirin. This reaction is known as Kolbe’s reaction.

  • Aspirin (2-acetoxybenzoic acid): It is prepared by treatment of salicylic acid with acetic anhydride. It is a component of aalgesics (tablets used for giving rlief in pain) and antipyretic (tablets used for reducing temperature of feveral body).


Chemistry Formulas

Class 12 chapter- Aldehyde & Ketone

  • Aldehydes : Those organic componds which have general formula

aldehyde. Their functional group is functional group Some of them are unpleasant smelling compounds. They contain carbonyl group attached with hydrogen. They are good reducing agents, e.g., HCHO (formaldehyde), CH3CHO (Acetaldehyde), etc.


Chemistry Formulas

Class 12 chapter- Amine

  • Amines : They are considered as amino derivatives of hydrocarbons or alkyl derivatives of ammonia. In these compounds, one, two or three hydrogen atoms are replaced by alkyl pr aryl groups. Aliphatic amino compounds are called amino alkanes and aromatic amines are called amino arenes, e.g., CH3NH2 (methanamine), C2H5NH2 (ethanamine), C6H5NH2 (benzenamine).
  • Among aliphatic amines the other of basic strength is
  1. R3N < RNH2 < R2NH in aqueous solution
  2. RNH2 < R2NH < R3N in acetic acid or chlorobenzene as solvent or in gaseous state.
  • amine

o-substituted amines are usually weaker bases than aniline irrespective of nature of substituents, i.e., electron withdrawing or releasing group due to ortho effect which is due to steric hindrance.

  • Amines can be separated by Hinsberg method using C6H5SO2 Cl or by Hofmanns method using hinsberg method (diethyl oxalate) which forms solid product with RNH2, liquid product with 2° amine and does not react with 3° amine.
  • The Schiff’s base formed by reaction of 1° amines with aldehydes are also called anils.
  • Amines having chiral ‘N’ -atom cannot be resoloved into enantiomeric forms because of rapid among flipping of one enantiomeric form into another.
  • 2° amine react with HNO2 forms nitrosoamine which on treatment with phenol and few drops of conc. H2SO4 forms green coloured solution.
  • This on treatment with aq. NaOH forms blue coloured solution which on dilution turns red.
  • This is test for 2° amine and called Liebermann’s nitroso reaction.
  • Nitrosoamines are carcinogens (cancenr causing)
  • Sulphanilic acid exists as zwitter ion, therefore, it is amphoteric in nature.
  • Aryl diazonium salts are more stable than alkyl diazonium salts.
  • In aromatic amines (C6H5)3N < (C6H5)2NH < C6H5NH2 < NH3 because phenyl group is electron withdrawing.


Chemistry Formulas

Class- 12 chapter- Biomolecules

  • Monosaccharides: These include nonhydrolysable carbohydrates. They are soluble in water. Those containing aldehydic 8. group are called aldose while other containing a ketonic group are called ketoses.
  • Disaccharides: Those carbohydrates, which on hydrolysis yield two molecules of monosaccharides are called disaccharides. They are crystalline, soluble in water and sweet in taste, e.g., cane sugar, maltose, lactose are disaccharides.
  • Oligosaccharides: Those carbohydrates which yield 2 to 10 monosaccharide molecules on hydrolysis are called is are called oligosaccharides, e.g., raffinose on hydrolysis give glucose, fructose and galactose,
  • Polysaccharides: Those carbohydrates, which produce large number of monosaccharide units are called polysaccharides. They are formed by linking together a large number of monosaccharide units through glycosidic linkage. Starch, amylose, amylopectin, glycogen, cellulose are examples of polysaccharides.
  • Sugars: In general monosaccharides and oligosaccharides are crystalline solids, soluble in water, sweet in taste. There are collectively called sugars, e.g., glucose, fructose, sucrose, etc.
  • Non-Sugars: The polysaccharides are amorphous, insoluble in water and tasteless are known as non-sugars, e.g., starch, cellulose, etc.
  • Reducing sugars: those carbohydrates which contain free aldehydic or ketonic group and reduce Fehling’s solution and Tollens’ reagent are called reducing sugars.
  • Non reducing sugars: Those sugars which do not have free aldehydic or ketonic group and do not reduce Fehling’s solution and Tollens’ reagent are called non-reducing sugars. In disaccharides if the reducing group of monosaccharide, i.e., aldehydic or ketonic groups are bonded, they are non-reducing sugars e.g., sucrose.
  • Mutarotation: When glucose was crystallised from a concentrated solution at 30°C, it gave α-form of glucose, melting point 146°C [α]D = +111° is specific rotation. On the other hand β-glucose has melting point 150°C and [α]D= +19.2° is obtained on crystallisation of glucose from a hot saturated aqueous solution at a temperature above 98°C. The two forms of glucose are called anomers and differ from each other in orientation of OH group at C-1. If either of the two forms is dissolved in water and allowed to stand, the specific rotation of a solution changes slowly and reaches a constant value at +52.5°.
  • Proteins: proteins are complex polyamides formed from amino acids. They are essential for proper growth and maintenance of body. They have many peptide bond. Therefore, proteins are long polymers of amino acids linked by peptide bonds (polypeptides).