GRB A TEXTBOOK OF PHYSICAL CHEMISTRY FOR NEET/IIT - EXAMINATION 2020-21

995 Pages·2020·71.35 MB·english

by  Dr. O.P TANDON

Chapters Pages
1-66
1.1 Chemistry and its Scope (1), 1.2 Brief History of Chemistry (2), 1.3 Matter and Energy (2), 1.4 Elements and
Compounds (4),1.5 Mixtures (6), 1.6 Alloys (7),1.7 Physical and Chemical Changes (8),1.8 Laws of Chemical
Combination (9), 1.9 Dalton's Atomic Theory (11), 1.1 0 Atoms, Molecules and Formulae (12), 1.11 Atomic and
Molecular Mass (13), 1.12 Avogadro's Hypothesis (16), 1.13 Mole Concept (17), 1.14 Equivalent Masses or
Chemical Equivalents (20),1.15 Methods for the Determination of Atomic Mass (21), 1.16 Types of Formulae
(23), 1.17 Percentage Composition of a Compound (23), 1.18 Determination of Empirical and Molecular
Formulae (25), 1.19 Chemical Equation (27), 1.20 Measurement in Chemistry: Fundamental and Derived Units
(28), Miscellaneous Numerical Examples (32), Summary and Important Points to Remember (39), Questions (42),
. Answers (43), Practice Problems (43), Objective Questions (48), Assertion-Reason Type Questions (55), Answers
to Objective and Assertion-Reason Type Questions (56), Brain Storming Problems for lIT Aspirants (57), Answers
(61), Integer Answer Type Questions (62), Answers (62), Linked Comprehension Type Questions (63), Answers
(65), SelfA ssessment (65),Answers (66).
67-149
2.1 Introduction (67),2.2 Cathode Rays-Discovery of Electron (67),2.3 Positive Rays-Discovery of Proton
(69),2.4 Rutherford Experiment-Discovery of Nucleus (69), 2.5 Moseley Experiment-Atomic Number (70),
2.6 Discovery of Neutron (71),2.7 Rutherford Model (71), 2.8 Electromagnetic Radiations (72), 2.9 Emission
Spectra-Hydrogen Spectrum (73),2.10 Quantum Theory ofR adiation (75), 2.11 Bohr's Atomic Model (78), 2.12
Sommerfeld's Extension of Bohr Theory (82), 2.13 Particle and Wave Nature of Electron (87),2.14 Heisenberg
Uncertainty Principle (88), 2.15 Wave Mechanical Model ofA tom (90),2.16 Quantum Numbers (92), 2.17 Pauli's
Exclusion Principle (96), 2.18 Aufbau Principle (97), 2.19 Hund's Rule of Maximum Multiplicity (Orbital
Diagrams) (98), Electronic Configuration of Elements (99); 2.20 Photoelectric Effect (101),2.21 Some other
Fundamental Particles (102), 2.22 Isotopes (102), 2.23 Theories of Nuclear Stability (103), 2.24 The Whole
Number Rule and Packing Fraction (104), 2.25 The Magic Numbers (104), Miscellaneous Numerical Examples
(106), Summary and Important Points to Remember (109), Questions (114), Answers (116), Practice Problems
(116), Objective Questions (123), Assertion-Reason Type Questions (136), Answers to Objective and Assertion
Reason Type Questions (137), Brain Storming Problems for lIT Aspirants (138), Answers (142), Integer Answer
Type Questions (143), Answers (143), Linked Comprehension Type Questions (144), Answers (147), Self
Assessment (148),Answers (149).
150-211
3.1 Radioactivity (150),3.2 Characteristics of Radioactive Radiations (150), 3.3 History of the Discovery of
Radioactivity (151),3.4 Analysis ofR adioactive Radiations (151), 3.5 Cause ofR adioactivity (152), 3.6 Theory of
Radioactive Disintegration (153), 3.7 Group Displacement Law (155), 3.8 Radioactive Disintegration Series
(157), 3.9 Rate of Disintegration and Half Life Period (158), 3.10 Average Life (162), 3.l1 Radioactive
Equilibrium (162), 3.12 Units of Radioactivity (163), 3.13 Artificial Transmutation (165), 3.14 Artificial
Radioactivity (167), 3.15 Nuclear Fission (167), 3.16 Nuclear Fusion (170), 3.17 Synthetic Elements Including
Transactinides (171), 3.18 Applications of Radioactivity (172), Miscellaneous Numerical Examples (175),
(viii)
Summary and Important Points to Remember (179), Questions (183), Answers (184), Practice Problems (185),
Objective Questions (189), Assertion~Reason Type Questions (198), Answers to Objective and Assertion-Reason
Type Questions (199), Brain Storming Problems for lIT Aspirants (200), Answers (204), Integer Answer Type
Questions (205), Answers (205), Linked Comprehension Type Questions (206), Answers (209), SelfA ssessment
(210),Answers(211).
212-315
4.1 Introduction (212), Section 1: Gaseous State-4.2 The Gaseous State (212), 4.3 Gas Laws (213), 4.4 Ideal
Gas Equation (215), 4.5 Dalton's Law of Partial Pressures (220), 4.6 Diffusion of Gases and Graham's Law of
Diffusion (221),4.7 Kinetic Theory of Gases (226), 4.8 Maxwell-Boltzmann Distribution of Molecular Speeds
(228),4.9 van der Waals' Equation (232), 4.10 Critical Phenomenon and Liquefaction of Gases (233), 4.10.1
Experimental Methods for Liquefaction of Gases (234), Section 2 : Liquid State-4.11 The Liquid State (242),
Section 3: Solid State-4.12 The Solid State (247), 4.13 Forms of Solids (248), 4.14 Isotropy and Anisotropy
(248),4.15 Differences between Crystalline and Amorphous Solids (248), 4.16 Types of Symmetry in Crystals
(249), 4.17 Space Lattice and Unit Cell (249), 4.18 Crystal Systems (250), 4.19 Designation of Planes in
Crystals-Miller Indices (251), 4.20 Crystallography and X-Ray Diffraction (252), 4.21 Analysis of Cubic
Systems (254),4.22 Packing ofIdentical Solid Spheres (258), 4.23 Types of Crystals (261), 4.24 Imperfection in
Solids (265), 4.25 Magnetic Properties (270), Miscellaneous Numerical Examples (273), Summary and Important
Points to Remember (276), Questions (282), Answers (283), Practice Problems (283), Objective Questions (288),
Assertion-Reason Type Questions (300), Answers to Objective and Assertion-Reason Type Questions (302), Brain
Storming Problems for lIT Aspirants (303), Answers (308), Integer Answer Type Questions (309), Answers (309),
Linked Comprehension Type Questions (31 0), Answers (313), SelfA ssessment (314), Answers (315).
316-390
5.1 Introduction (316), 5.2 Solvent and Solute (316), 5.3 Types of Solutions (316), 5.4 Methods of Expressing the
Concentration of a Solution (316), 5.5 Solutions of Gases in Liquids (Solubility of Gases) (322), 5.6 Solutions of
Liquids in Liquids (325), 5.7 Theory of Fractional Distillation (329), 5.8 Solutions of Solids in Liquids (330), 5.9
Colligative Properties of Dilute Solutions (332), 5.10 Lowering in the Vapour Pressure (332), 5.11 Elevation of
Boiling Point (Ebullioscopy) (336), 5.12 Depression of Freezing Point (Cryoscopy) (338), 5.13 Osmosis and
Osmotic Pressure (342), 5.14 van't Hoff Theory of Dilute Solutions (344), 5.15 Determination of Molecular
Masses (345), 5.16 Reverse Osmosis (347), 5.17 Abnormal Colligative Properties (347), Miscellaneous
Numerical Examples (352), Summary and Important Points to Remember (356), Questions (360), Answers (360),
Practice Problems (361), Objective Questions (365), Assertion-Reason Type Questions (378), Answers to
Objective and Assertion-Reason Type Questions (379), Brain Storming Problems for lIT Aspirants (380),
Answers (385), Linked Comprehension Type Questions (386), Answers (388), Self Assessment (389), Answers
(390).
391-419
6.1 Introduction (391), 6.2 Particle Size and Colloidal State (391), 6.3 Types of Colloidal Solutions (392), 6.4
Preparation of Colloidal Solutions (393),6.5 Purification of Colloidal Solutions (394),6.6 Properties of Colloidal
Solution (395),6.7 Emulsions (399),6.8 Classification of Colloids Based on the Type ofPartidt:s of Dispersed
Phase (399), 6.9 Gels (40 I), 6.10 Applications of Colloids (402), Summary and Important Points to Remember
(403), Questions (405), Answers (406), Objective Questions (406), Assertion-Reason Type Questions (413)
Answers to Objective and Assertion-Reason Type Questions (414), Brain Storming Problems for lIT Aspirants
(415), Answers (416), Linked Comprehension Type Questions (416), Answers (417), Self Assessment (418),
Answers (419).
(ix)
les AND
420-517
7.1 Introduction (420),7.2 Terms Used in Thermodynamics (420), 7.3 Internal Energy (424), 7.4 First Law of
Thermodynamics (425),7.5 Enthalpy (426), 7.6 Heat Capacity (426),7.7 Expansion of an Ideal Gas (427), 7.8
Graphical Representation of various Thermodynamic Processes and the Calculation of Work done by Graphical
Methods (429), 7 .9 louie-Thomson Effect (430), 7.1 0 Thermochemistry (434),7.11 Heat of Reaction or Enthalpy
ofR eaction (434), 7.12 Enthalpy of Formation or Heat of Formation (436), 7.13 Enthalpy of Combustion or Heat
ofC ombustion (437), 7.14 Enthalpy of Solution or Heat ofS olution (439), 7.15 Enthalpy ofN eutralisation or Heat
ofNeutralisation (439),7.16 Enthalpies ofP hysical Changes (Phase Changes) (441),7.17 Hess's Law (The Law of
Constant Heat Summation) (441), 7.18 Influence of Temperature on the Heat of Reaction or Kirchhoff's
Equation (444), 7.19 Bond Energy or Bond Enthalpies (444), 7.20 Determination of Lattice Energy (Born-Haber
Cycle) (450), 7.21 Experimental Determination of the Heat of Reaction (451), 7.22 Limitations of First Law of
Thermodynamics (452), 7.23 Spontaneous and Non-spontaneous Processes (453), 7.24 Entropy (456), 7.25
Entropy Change During Phase Transitions (458), 7.26 Second Law of Thermodynamics (460), 7.27 Gibbs Free
Energy, (G), Change in Free Energy and Spontaneity (461), 7.28 Standard Free Energy Change (466), 7.29
Relationship between Standard Free Energy Change (aG") and Equilibrium Constant (466), 7.30 Physical
Significance of Gibbs Free Energy Change (Free Energy and Useful Work) (469), 7.31 Absolute Entropies and
Third Law of Thermodynamics (469), 7.32 Conversion of Heat into Work-The Carnot Cycle (471),
Miscellaneous Numerical Examples (473), Summary and Important Points to Remember (477), Questions (481),
Answers (482), Practice Problems (482), Objective Questions (489), Assertion-Reason Type Questions (501),
Answers to Objective and Assertion-Reason Type Questions (503), Brain Storming Problems for lIT Aspirants
(504), Answers (509), Integer Answer Type Questions (510), Answers (510), Linked Comprehension Type
Questions (5II),Answers(515), SelfAssessment(515),Answers(517).
518-591
8.1 Introduction (518),8.2 Rate of Reaction (Average and Instantaneous Rate) (519), 8.3 Law of Mass Action
(Guldberg and Waage, 1864) (523), 8.4 Rate Constant (523),8.5 Collision Theory of Reaction Rate (Arrhenius
Theory of Reaction Rate) (524), 8.6 Molecularity of Reaction (529),8.7 Order of Reaction (530),8.8 Pseudo
Order Reaction (531),8.9 Reaction Mechanism (535), 8.10 Reactions of Various Orders (536),8.11 Methods for
Determination of Order of a Reaction (540), Miscellaneous Numerical Examples (548), Summary and Important
Points to Remember (554), Questions (557), Answers (558), Practice Problems (558), Objective Questions (565),
Assertion-Reason Type Questions (579), Answers to Objective and Assertion-Reason Type Questions (580), Brain
Storming Problems for lIT Aspirants (581), Answers (586), Integer Answer Type Questions (586), Answers (586),
Linked Comprehension Type Questions (587), Answers (588), SelfA ssessment (589), Answers (591).
592-655
9.1 Introduction (592), 9.2 State of Chemical Equilibrium (593), 9.3 The Law of Chemical Equilibrium
(Application of Law of Mass Action) (594). 9.4 Reaction Quotient or Mass Action Ratio (597), 9.5 Activation
Energies for Forward and Backward Reactions (599), 9.6 Standard Free Energy Change of a Reaction and its
Equilibrium Constant (600),9.7 Equilibrium Constant Expressions for Some Reactions (601), 9.8 Le Chatelier's
Principle (608), 9.9 Application of Le Chatelier's Principle to Physical Equilibria (610), 9.10 Calculation of
Degree ofD issociation from Density Measurements (611), Miscellaneous Numerical Examples (612), Summary
and Important Points to Remember (621), Questions (624), Answers (625), Practice Problems (625), Objective
Questions (629), Assertion-Reason Type Questions (643), Answers to Objective and Assertion-Reason Type
Questions (644), Brain Storming Problems for lIT Aspirants (645) , Answers (649), Integer Answer Type Questions
(650), Answers (650), Linked Comprehension Type Questions (651), Answers (653), Self Assessment (654),
Answers (655).
(x)
IONICEQUILI.BR1U M 656-731
10.1 Introduction (656), 10.2 Ostwald's Dilution Law (656), 10.3 Common Ion Effect (658), 10.4 Solubility
Product (660), 10.5 Acids and Bases (668), 10.6 Relative Strength of Acids and Bases (671), 10.7 Acid-Base
Neutralisation-Salts (673),10.8 Ionic Product of Water (674),10.9 Hydrogen Ion Concentration-pH Scale
(675),10.10 pH of Weak Acids and Bases (676)g 10.11 Buffer Solutions (679),10.12 Salt Hydrolysis (686), 10.13
Theory of Indicators (693), Miscellaneous Numerical Examples (695), Summary and Important Points to
Remember (700), Questions (705), Answers (706), Practice Problems (706), Objective Questions (711),
Assertion-Reason Type Questions (726), Answers to Objective an~Assertion-Reason Type Questions (727), Brain
Stormingl?roblems for lIT Aspirants (728), Answers (732), Integer Answer Type Questions (732), Answers (732),
Linked Comprehension Type Questions (733),Answers (735), SelfA ssessment (736), Answers (737).
9~t~[)J.\'fIO,NJ.\'NDREDUCTIOi" '(Redox ReacUons~ 738--173
_. __ -,. -. "U _ _ ,__ Uu _.:. _ - ,
11.1 Molecular and Ionic Equations (738), 11.2 Oxidation and Reduction (739), 11.3 Modem Concept of
Oxidation and Reduction (740), 11.4 Ion-Electron Method for Balancing Redox Reactions (741), 11.5 Oxidation
Number (Oxidation State) (743), 11.6 Special Examples of Oxidation State Determination (745), 11.7 Oxidation
Numbers (States) in Different Types of Elements (747), 11.8 Valency and Oxidation Number (748), 11.9 Balancing
Oxidation-Reduction Reactions by Oxidation Number Method (749), 11.10 Disproportionation and Oxidation
Reduction (751),11.11 Autoxidation (752),11.12 Formal Charge (752),11.13 Stock Notation (753),11.14
Stoichiometry of Redox Reactions in Solutions (753), Summary and Important Points to Remember (754),
Questions (756), Answers (759), Objective Questions (760), Assertion-Reason Type Questions (766), Answers to
Objective and Assertion-Reason Type Questions (767), Brain Storming Problems for lIT Aspirants(768), Answers
(769), Integer Answer Type Questions (770), Answers (770), Linked Comprehension Type Questions (771),
Answers (772), SelfA ssessment (772),A:nswers (773).
Elf;CT,ROC'H,EMISTRV 774-865
,<i.,.f-.o;1 '-~_:.;. :j'''; <. ; ,',
Section 1: Electrolytes and Electrolysis-12.1 Introduction (774), 12.2 Preferential Discharge Theory (775),
12.3 Faraday's Laws of Electrolysis (776), 12.4 Applications of Electrolysis (778), Section 2: Conductance and
Conductors-12.5 Arrhenius Theory of Electrolytic Dissociation (784), 12.6 Factors Pertaining to Degree of
Ionisation (786), 12.7 Electrolytic Conductance (786), 12.8 Kohlrausch's Law (789), 12.9 Theory of Weak
Electrolytes (789), Section 3 : Electrochemical Cell-12.l0 Electrochemical Cell (792), 12.11 Daniell Cell
(792), 12.12 Salt Bridge and Its Significance (793), 12.13 Representation of an Electrochemical Cell (Galvanic
Cell) (794), 12.14 Electrode Potential (794), 12.15 Standard Electrode Potential (795), 12.16 Reference Electrode
(Standard Hydrogen Electrode, SHE or NHE) (795), 12.17 Measurement of Electrode Potential (795), 12.18 EMF
of a Galvanic Cell (797), 12.19 Reversible and Irreversible Cells (797), 12.20 Some other Reference Electrodes
(797), 12.21 Prediction for Occurrence of a Redox Reaction (798), 12.22 Electrode and Cell Potentials-Nemst
Equation (798), 12.23 Electrochemical Series (803), 12.24 Primary Voltaic Cell (The Dry Cell) (808), 12.25
Secondary Voltaic Cell (Lead Storage Battery) (809), 12.26 Fuel Cell (809), 12.27 Concentration Cells (809),
12.28 Commercial Production of Chemicals (811), Miscellaneous Numerical Examples (816), Summary and
Important Points to Remember (824), Questions (829), Answers (830), Practice Problems (831), Objective
Questions (839), Assertion-Reaso)}. Type Questions (852), Answers to Objective and Assertion-Reason Type
Questions (853), Brain Storming Problems for lIT Aspirants (854), Answers (858), Integer Answer Type Questions
(859), Answers (859), Linked Comprehension Type Questions (860), Answers (863), Self Assessment (863),
Answers (865).
866-899
Adsorption : 13.1 Introduction (866), 13.2 Distinction between Adsorption and Absorption (866), 13.3
Mechanism of Adsorption (867), 13.4 Types of Adsorption (Adsorption of Gases) (867), 13.5 Adsorption
Isotherms (868), 13.6 Adsorption from Solution Phase (870), 13.7 Adsorption Isobars and Isostere (870),
(xi)
13.8 Applications of Adsorption (871), Catalysis : 13.9 Introduction (872), 13.10 Homogeneous and
Heterogeneous Catalysis (872), 13.11 Types of Catalysis (873), 13.12 Characteristics of Catalysis (874), 13.13
Theories of Catalysis (876), 13.14 Acid-Base Catalysis (878),13.15 Enzyme Catalysis (879),13.16 Catalysts in
Industry (882), 13.17 Zeolites (883), 13.18Automobile Catalytic Converter (883), Summary and Important Points
to Rqmember (884), Questions (886), Answers (886), Practice Problems (887), Objective Questions (888),
Assehion-Reason Type Questions (893 ),Answers to Objective and Assertion-Reason Type Questions (894), Brain
Storming Problems for lIT Aspirants (895), Answers (897), Linked Comprehension Type Questions (897),
Answers (897), SelfA ssessment (898), Answers (899).
~()LUMETRICANALYSIS 900-945
14.1 Important Termed used in Volumetric Analysis (900), 14.2 Concentration Representation of Solution (900),
14.3 Classification of Reactions Involved in Volumetric Analysis (901),14.4 Calculation of Equivalent Mass of
Different Substances (902),14.5 Acid-Base Titrations (907),14.6 Titration of Mixture of NaOH, Na2C03 and
NaHC03 by Strong Acid Like HCl (908),14.7 Redox Titrations (916),14.8 Iodometric and Iodimetric Titrations
(916), Questions (926), Answers (931), Objective Questions (932), Assertion-Reason Type Questions (937),
Answers to Objective and Assertion-Reason Type Questions (937), Brain Storming Problems for lIT Aspirants
(938), Answers (941), Linked Comprehension Type Questions (942), Answers (944), Self Assessment (944),
Answers (945).
_,,~!()~'qH10METRY. (Chemical Formulae and Equations) 946-967
Stoichiometry : Quantitative Relations in Chemical Reactions (946), Miscellaneous Numerical Examples (954),
Questions (957), Answers (958), Objective Questions (959), Answers to Objective Questions (962), Brain Storming
Problems for lIT Aspirants (963), Answers (965), Linked Comprehension Type Questions (966), Answers (966), Self
Assessment (967),Answers (967).
SPONTANEOUS ASSESSMENT SECTION
iil liT ENTRANCE TEST PAPER: MODULE-1 968-971
iil liT ENTRANCE TEST PAPER: MODULE-2 972-975
iil liT ENTRANCE TEST PAPERS
• Test Series I 976
Answers with Hints for Selected Questions 981
• Test Series II (Graphical Aptitude) 983
Answers 989
• Test Series HI (Test of Matching Aptitude) 990
Answers 993
• Test Series IV (Test of Reasoning Aptitude) 994
Answers 994
iil LOG TABLE 995
iil ANTILOG TABLE 996
1
BASIC PRINCIPLES'
1..1' CHEMISTRY AND ITS SCOPE (2) Inorganic chemistry: It deals with the study of all
known elements and their compounds except organic
Chemistry is a branch ofp hysical science which deals with the
compounds. It is concerned with the materials obtained from
study ofm atter, its physical and chemicalproperties, its chemical
minerals, air, sea and soil.
composition, the physical and chemical changes which it
(3) Physical chemistry: It is concerned with the physical
undergoes and the energy changes that accompany these
properties and constitution of matter, the laws of chemical
processes.
combination and theories go.verning reactions. The effect of
All objects in this universe are composed of matter. Most of temperature, pressure, light, concentration, etc., on reactions
these objects are visible (solids and liquids) but some are
come under the scope of physical chemistry.
invisible. Chemistry is termed as a material science because it is
(4) Analytical chemistry: It deals with various methods of
concerned with all material substances such as air, water, rocks,
analysis of chemical substances both qualitative and quantitative.
minerals, plants, animals including man, the earth on which we
It includes chemical and physical methods of analysis.
all live, and other planets. According to one of the famous
A number of specialised branches have been introduced as to
scientists of twentieth century, Linus Pauling, Chemistry is the
cope with the extraordinary expansion in the subject of
science of substances, their properties, their structure and their
chemistry. Some of the specialised branches are:
transformations.
(i) Biochemistry: It comprises the studies of the substances
Chemistry is a very interesting subject which touches almost
related to living organisms and life processes.
every aspect of our lives, our culture and our environment. It has
(ii) Medicinal chemistry: It deals with the application of
changed our civilization to a great extent. The present day
chemical substances for the prevention and cure of various
chemistry .has provided man with more comforts for a healthier
diseases in living 'beings.
and happier life. A large number ormaterials which we use these
(iii) Soil and agriculture chemistry: It deals with the:
days were unknown at the turn of the century. A few decades
analysis and treatment of soils so as to increase its fertility for the'
back, our clothes and footwears were exclusively of natural
better yields of crops. It is concerned with the chemicals used as
origin such as vegetable fibres, wool, hair, skin of animals, etc.,
fertilizers, insecticides, germicides, herbicides, etc.
but, now the synthetic fibres produced in chemical factories have
largely replaced them. Modem chemistry has given man new (iv) Geochemistry: It includes the study of natural
substances like ores and minerals, coal, petroleum, etc.
plastics, fuels, metal alloys, fertilizers, building materials, drugs,
energy sources, etc. (v) Industrial chemistry: It deals -with the study of
chemical processes for the production of useful chemicals on a
During the last few decades, the expansion of chemistry has
large scale at relatively low costs.
been tremendous. The field has become wide and complex. For
convenience and better understanding of the subject, it has been (vi) Nuclear chemistry: It is the most recent branch. It
divided into various branches. The four main branches of includes the study of nuclear reactions, the' production of
chemistry are: radioactive isotopes and their applications in various fields.
(1) Organic chemistry; (2) Inorganic chemistry; (vii) Structural chemistry: It deals with various
techniques used for elucidation of the structure of chemical
(3) Physical chemistry; (4) Analytical chemistry.
substances. It is concerned with the properties of substances in
(1) Organic chemistry: It is concerned with the study of
terms of their structure.
compounds of carbon except carbonates, bicarbonates, cyanides,
isocyanides, carbides and oxides of carbon. It is actually the (viii) Polymer chemistry: It includes the study of chemical
study of hydrocarbons and their derivatives. substances of very high molecular masses of the order of 100,000
or greater, called polymers-natural or artificial. This branch is
2 G.R.B. PHYSICAL CHEMISTRy.fDR COMPETITIONS
gaining popularity as the use of plastics, rubber, synthetic fibres, Pri~~tley and Carl Scheele. Priestley was a very conservative
silicones, etc., is on the increase thes~ days. scientist. Even after his discovery of oxygen, he still believed in
(ix) Limnochemistry: It deals with the study of chemistry phlogiston theory.
involved in the river water or water reservoirs. (v) Modern period: Lavoisier (1743-1793), a French
(x) Phytochemistry: It includes the study of chemistry of plants. chemist, is regarded as the father of modern chemistry. He
presented the exact explanation of combustion by proposing that
Thus, it can be said iliat theteisno othel'bfaQ,c1(ofscience
~4ichis so wide in its<scope as cheniistty;" . " . oXY8¢I1 is necessary for combustion. This concept was largely
responsible for the overthrow of the phlogiston theory. Among
t~2 aRIEFHISTORY OF CHEMISTRY his other contributions, he showed that water is composed of
hydrogen and oxygen, proposed the theory of indestructibility of
It is difficult to specify the date when science of chemistry came fl\atter, presented a clear defmition of an element and proposed a
into existence; however, its 'groWtli must have gone side by side system of chemical nomenclature.
with the growth of civilization. Broadly, the history of chemistry
Another major step towards modem chemistry was taken in
can be studied under five periodS of its development.
the first decade of the nineteenth century when the English
(i) Ancient period up to 350 A.D.: In ancient times, many chemist, John Dalton, postulate~ that all elements are made up
chemical operations such as souring of milk, conversion of sweet of atoms. He pictured atoms as tiny, indestructible units that
juices into wines, the conversion of wines into vinegar, etc., were could combine to form compound atoms or molecules. Dalton
known: Around3000,RC'" techniques of making glass, pottery, proposed that each element has its own kind of atom,s and the
pigments, dyes, perfuines and extraction of metals especially atoms of different elements differ in essentially nothing but their
gold* and silver were known in China, India, Egypt and Greece. masses. He determined the relative fl\asses of atoms of many
The beginning of chemistry as a science could probably be set elements. Thus, a new era had begun. The other important
about 400 B.c., when the theory was proposed that everything is chemists of this period are:
cOlllPosed of four elements: earth, air, fire and water. The first
(a) Richter-Law of Reciprocal Proportions (1794)
.. bQOkof chemistry was written in Egypt around 300 A.D. The
(b) Proust-Law of Definite Proportions (1799)
terril chemistry meant the Egyptian art.
(c) Gay-Lussac-Law of Combining Volumes of Gases
(ii) The aicli"emicai period (350-1500): During this
(1808)
period, scientists called alchemists tried to discover two things:
(d) Avogadro-Avogadro Hypothesis (1811)
an elixir of life which could make m:an eternally young and a
(e) Berzelius-Introduced the Modem Symbols for
philospher's stone which could transmute base metals like zinc,
Elements (1813)
copper, iron, etc., into gold. The alchemists failed in their efforts
(f) Faraday-Laws of Electrolysis (1833)
because no philospher's stone and elixir of life actually existed
(g) Thomas Graham""':"'Law of Gaseous Diffusion (1861)
but we are indebted to them for designing new types ofa pparatus
and for discovering new chemical operations such as distillation, (h) Mendeleev-Periodic Law and Periodic Table (1869)
sublimation, e~traction of gold by amalgamation process and (i) Arrhenius-TheoryofIonization (1887)
preparation of caustic alkalies from ashes of plants., (j) Henry Becquerel-Discovery of Radioactivity (1896)
(iii) tlatro chemistry period (i500~1650): . During this (k) Madam Curie-Discovered Radium and Polonium
era, chemists paid their attention towards medico-chemical (1898)
problems. They believed tllat the primary object Of c4emistry was The twentieth century is' regarded as an active era of
to prepare medicines and not to make gold from base metals. chemistry. During this period, chemistry has fl\ade many
DUring this period, the study of gases was begun and quantitative contributions to human knowledge and civilization. Now, we live
experiments were undertaken for the first time. Robert Boyle in a world of synthetic fl\aterials. Chemistry of today is actually
(1627-1691) found that when it metal is heated in air, the mass· helping in solving major problems of our present day civilization
increases. He also established the relationship between volume such as population explosion, food and diseases, depletion of
and pressure of a gas. In 1661, Boyle wrote. the book 'The sources of energy, depletion of natural sources and environmental
Skeptical Chyrnist' in which he criticised' the hasic ideas of pollution ..
alchemy.
(iv) The phlogiston period (1650-1774): The phlogiston 1::~, MATTER AND ENERGY
theory was proposed by Ernst Stahl (1660-1734). Phlogiston
Besides life, matter a~denergy are regarded the two fundamental
was described as a substance in a combustible fl\aterial which is
entities with which whole of the universe is composed of. Matter
given off when the material bun:J.s. This theory persisted for about,
is anything that has mass and occupies space. All bodies in the
100 years arid was a centre of much controversy. During the end
universe conform to this definition. Mass is the quantity of matter
of the eighteenth century, much work was done with gases,
in a particular sample of matter. Mass ofa body is constant and
especially by Joseph Black, Henry Cavendish, Josepth
does not change regardless of where it is measured. The mass of a
-",. ~ . '
*Gold was probably the ftrst metal to be used because it occurred as a free metal in the earth. :
t Iatro is a Greek word m~aning a physician.
3
BASIC PRINCIPLES
body would be the same on the moon as it is on the earth. Our structure and are very near to one another. This form of matter is
senses of sight and touch usually tell us that an object occupies associated with minimum amount of energy.
space except in the case of colourless, odourless and tasteless in liquid state, substances have no definite shape but possess a
gases where some other evidence is required to satisfy the fixed volume. There is slight effect of pressure and temperature
definition of matter. on their volumes. They have the ~perty of flowing. The
The term weight should not be used in place of mass as it has a particles are nearer to one another than in a gas and this form of
different meaning. The term weight refers to the force with which matter is associated with energy more than solids.
an object is attracted towards earth. An object resting on earth In a gaseous state, substances have no definite shape and
experiences a force called its weight, W, that is equal to its mass volume. Gases fill completely any vessel in which they are
m, mUltiplied by the acceleration due to gravity g, thatis, confined and thus occupy the whole space available to them.
W=mg There is a large effect of pressur-eand temperature on their
The weight of an object thus depends on the value of' g' which volumes. The particles are far apart from one another and move
with very high speeds in all possible directions. This form of
varies from place to place. However, the mass of an object is
matter is associated with maximum amount of energy.
determined by comparing the weights of two objects, one of
known mass, the other of unknown mass in the same location on Sublimation
earth as both experience the same gravitational acceleration.
Matter is indestructible, i, e., it can -neither be -created, nor Solidification
Solid Liquid , Gas
destroyed, but it can change its form; thus, the total quantity of
matter of the universe is constant. ' .~~
Energy is defined as the capacity of doing work.
Freezing Condensation
Anything which has the capacity to push the matter from one place
to another possesses energy. There are various forms of energy + energy + energy
such as heat, light, etc. Energy is neither created, nor destroyed, but Solid '~ Liquid ~ Gas
-energy . ,-energy
can only be transformed from one form of energy to another.
AbsorPtion 'of energy
The world became aware of the fact that matter can be
converted into energy with the discovery of nuclear reactions, Release of energy
especially nuclear fission and nuclear fusion. The relationship Depending on temperature and pressure, a substance can exist
between mass and energy was given by Einstein. The. famous in anyone of the three forms of matter.
relation is: ... ' (ii) Chemical classification: Matter exists in nature in the
E =mc2 form of chemical substances. A pure substa~ce is defined as a
variety of matter, all samples of which have same composition
where, E = energy, m = mass and c = velocity of light.
and properties. Pure substances are divided into elements and
On account of this equation, the 'above two 'laws are
compounds. Most of the materials found in nature are in the. form
amalgamated into a single statement:
of mixtures consisting of tWo or more substances. There are two
"The total amount of matter and energy available in the
types of mixtures-Homogeneous and Heterogeneous. Both
universe is fIXed."
types of mixtures can be separated into their components (pure
Example 1. Calcula(e the amount of energy released in substances) by mechaniCal and physical methods. Th~
ergs, calories and in joules when 0.001 kg ofm ass disappears. classification can be summarized in the following way:
[Given, Velocity of light = 3 X 108 ms-1]
Matter
Solution: According to Einstein equation, E lne2 I '
m=0.00Ikg=lxlO-3 kg;c=3xI08 ms-1 I
E (1 x 10-3 )(3 X 108)2 = 9x 1013 J Physical classification Chemical classification
lJ = 107 erg = 0.24 cal 1 1 . r 1
9xlO13 J 9xlO13 xl07 erg=9x1013 x 0.24 cal Solids Liquids Gases Mixtures Physical Pure,
= 9 x 1020 erg 2.16 x 1013 cal I me.~ods substances
I 1 '
ClaSSification of Matter
Homogeneous Heterogeneous
(i) Physical classification:, Matter can exist in anyone of
three forms, (a) solid, (b) liquid and (c) gas:
Chemical
Compounds Elements
In the solid state, substances are rigid. They have a definite
methods
shape and fixed volume. There is negligible effect of changes in
pressure and temperature on their volumes. The individual
particles that make up a solid occupy definite positions in the Inorganic Organic
4 G.R.B. PHYSICAL CHEMISTRY FOR COMPETITIONS
Properties of Matter: Properties are the characteristic (iii) or from names of the elements in other languages such as
qualities with the help of which different kinds of matter can be Latin, German, etc.
commonly recognised. In chemistry, substances are distinguished Na-Sodium (Latin name Natrium)
by two types of properties, viz (i) Chemical properties and (ii)
Cu-Copper (Latin name Cuprum)
Physical properties.
Fe---Iron (Latin name Ferrum)
The chemical properties of substances are those in which they
undergo change in composition either alone or by interactions with Ag-Silver (Latin name Argentum)
other substances, i. e., to form new substances having different Pb-Lead (Latin name Plumbum)
compositions from the substances which undergo change. Au-Gold (Latin name Aurum)
The properties of substances which are observed in absence of
K-Potassium (Latin name Kalium)
any change in composition under specific physical s~ate are
Hg-Mercury (Latin name Hydragyrum)
termed physical properties. Colour, density, melting point,
boiling point, hardness, refractive index, thermal conductivity, W-Tungsten (German name Wolfram)
electrical conductivity, malleability, ductility, etc., are some Out of 117 elements known, 88 have been isolated from
examples of the physical properties. The properties of matter can natural sources and the remaining have been prepared by
be further classified into two: (i) Intensive properties and (ii) artificial means. The man made elements are:
Extensive properties. The intensive properties are those which
S.No. Name Symbol S.No. Name Symbol
do not depend upon the quantity of matter, e.g. , colour, density,
melting point, boiling point, refractive index, etc. These 1. Neptunium Np 16. Hassium or Hs or
properties are same irrespective of the quantity of the substance. Unniloctium Uno
Chemical properties are also intensive properties. The extensive
2. Plutonium Pu 17. Meitnerium or Mtor
properties of matter depend on the quantity of matter. Volume,
Unnilennium Une
mass, weight, energy, etc., are the extensive properties.
3. Americium Am 18. Ununnilium Uun
:1;4 ELEMENTS AND COMPOUNDS
4. Curium Cm 19. Unununium Uuu
Elements are pure substances that cannot be decomposed into 5. Berkelium Bk 20. Ununbium Uub
simpler substances by chemical changes. The smallest particles
6. Californium Cf 21. Ununtrium Uut
of an element possess the same properties as the bigger particles.
An element can also be defined as a pure substance which 7. Einsteinium Es 22. Ununquadium Uuq
consists of only one type of atoms. Due to discovery of isotopes, 8. Fermium Fm 23. Ununpentium Uup
this definition does not seem to be correct. The modem definition
9. Mendelevium Md 24. Ununhexium Uuh
of an element is that it is a simple individual which has a definite
atomic number (see atomic structure) and has a defmite position in 10. Nobelium No 25. Ununoctium Uuo
the periodic table. It carmot be decomposed in a chemical change.
11. Lawrencium Lr 26. Technetium Tc
In chemistry, the elements are the chemical alphabet and
compounds are the words, i. e. , combinations of elements. 12. Kurchatovium Ku 27 Promethium Pm
There are presently 117 different elements known. Every 13. Hahnium Ha 128.• Astatine At
element has been given a definite name and for convenience a
14. Seaborgium or Sg or Francium Fr
nick name which in· chemical language is called a symbol. \29.
Unnilhexium Unh
Symbol is a small abbreviation to represent a full and lengthy
name oft he element. Symbols have been derived: 15. Nielsbohrium or Bhor
Unnilseptium Uns I
(i) either by taking the first letter of the name of the element
which is capitalized: The elements from S. No. 1 to 25 are called transuranic
O-Oxygen N-Nitrogen F-Fluorine elements. The credit for the discovery of most of the transuranic
elements goes to the scientist G.T. Seaborg. The first artificially
C-Carbon H-Hydrogen U-Uranium
produced element was technetium. It was synthesised in 1937 by
P-Phosphorus S-Sulphur 1-Iodine
scientists at the University of California at Berkley.
(ii) or by taking the first letter and one more letter from the Most of the earth's crust is made up of a small number of
name of the element. The first letter is always capitalized.
elements. Only ten of the naturally occurring elements make up
Ca-Calcium Ni-Nickel AI-Aluminium 99% mass of the earth's crust, oceans and atmosphere. The
Mg-Magnesium Co-Cobalt Bi-Bismuth following table shows the abundance of highly abundant
elements in nature:
CI-Chlorine Br-Bromine Sa-Barium
l
Note: Among the naturally occurring elements, H is lightest and 2~~ U is the heaviest atom.
l
I'
5
BASIC PRINCIPLES
Abundance of Elements (Earth's Crust, Oceans and generally (i) brittle, (ii) non-lustrous, (iii) having low melting
Atmosphere) and boiling points, (iv) non-conductors of heat, (v) capable of
forming acidic oxides or neutral oxides, (vi) not capable of
Oxygen 49.5% Chlorine 0.19%
evolving hydrogen from acids, and (vii) capable of forming
Silicon 25.7% Phosphorus 0.12%
volatile hydrides.
Aluminium 7.5% Manganese 0.09% There are some elements which do not fit completely into
Iron 4.7% Carbon 0.08% either the metal or non-metal class. Elements which have some
Calcium 3.4% '$. Sulpur 0.06% '$. properties of both metals and non-metals are called semi:metals
N
0\ t'- or metalloids. The semi-metals are silicon, germanium, arsenic,
Sodium 2.6% 0\ Barium 0.04% d
antimony and tellurium. .
Potassium 2.4% Chromium 0.033%
The above classification of elements is a rough one as certain
Magnesium 1.9% Nitrogen 0.030% metals. like lithium, sodium, potassium possess low density;
Hydrogen 0.87% Fluorine 0.027% certain non-metals like hydrogen and graphite (a form of carbon)
Titanium 0.58% Zirconium 0.023% are good conductors of electricity. Metals rarely combine with
one another while non-metals combine with one another to form
If the entire universe is considered, then 90% of matter is
compounds. Metals and non-metals commonly combine with .
hydrogen. Helium is the second most abundant element
each other to form compounds.
amounting to 9% and the remaining elements make up only 1%
of the universe with oxygen, neon, carbon and nitrogen next in
Compounds
order of decreasing abundance.
Compounds are also pure substances that are composed of
The commercial use of an element depends not only upon its
two or more different elements in a fixed proportion by mass.
abundance but also upon its accessibility. Some of the common
Compounds containing more than four elements are rare. The
elements such as copper, zinc, tin and lead are not abundant but
properties of a compound are altogether different from the
are found in nature in rich deposits from which these can be
properties of the elements from which it has been constituted.
easily extracted. On the other hand, the elements such as titanium
and zirconium which are found in abundance in nature are not The compound water has a definite composition, i. e., 11.2%
widely used because their ores are not rich and their extraction is hydrogen and 88.8% oxygen, Thus, the two are present in the
difficult and expensive. ratio of 1 : 8 by mass. The properties of water are totally different
from the properties of hydrogen and oxygen both. Hydrogen and
Metals, Non-metals and Metalloids oxygen are in gaseous state while water is in liquid state under
ordinary atmospheric conditions. Oxygen supports combustion
All the elements may be classified into two groups, metals
while hydrogen is combustible but water is normally used for
and non-metals. The division is based on both physical and
extinguishing fire. Component elements in compounds can be
chemical properties.
separated only by chemical means and not by physical methods.
Metals are regarded as those elements which possess the
Compounds are classified into two types:
following properties:
(i) Organic compounds: The' compounds obtained from
(i) They are generally solids at ordinary conditions. Mercury
living sources are termed organic compounds. The term organic
is an exception which is in liquid state.
is now applied to hydrocarbons (compounds of carbon and
(ii) They are lustrous in nature. hydrogen) and their derivatives.
(iii) They possess high density.
(ii) Inorganic compounds: .! The compounds obtained from
(iv) They are good conductors of electricity and heat. non-living sources such as roc~ and minerals are termed
(v) They are malleable and ductile. inorganic compounds. The compounds of all elements except
(vi) They possess generally high melting and boiling points. hydrocarbons and their derivatives are included in this category.
(vii) They react with mineral acids liberating hydrogen. The number of organic compounds is very large in comparison to
inorganic compounds.
(viii) They form basic oxides.
Some Specific Properties of Substances: Some specific
(ix) They form non-volatile hydrides if combine with
properties of substances are given below:
hydrogen.
(i) Deliquescence: The property of certain compounds of
(x) They have molecules usually mono-atomic in the vapour
taking up the moisture present in atmosphere and becoming wet
state.
when exposed, is knpwn as deliquescence. These compounds are'
Sodium, calcium, aluminium, copper, silver, zinc, iron, nickel,
known as deliquescent. Sodium hydroxlde, potassium hydroxide,
gold, mercury, etc., are the examples of metals.
anhydrous calcium chloride, anhydro;us magnesium chloride,
The non-metals do not show the above properties. Six of the anhydrous ferric chloride, etc., are the hamples of deliquescent
non-metals, carbon, boron, phosphorus, sulphur, selenium and compounds. Sodium chloride is noti deliquescent but when
iodine, are solids. Bromine is the only liquid non-metal at room common salt is placed in atmosphere it becomes wet due to
temperature and normal pressure. The remaining non-metals; presence of an impurity of magnesium chloride.
nitrogen, oxygen, fluorine, chlorine, hydrogen, helium, argon, (ii) Hygroscopicity: Certain compounds combine with the
neon, krypton, xenon and radon are gases. Non-metals are moisture of atmosphere and are converted into hydroxides or