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CONTENTS
No. Unit Page No.
1. Some Basic Concepts of Chemistry 2 – 10
2. Structure of Atom 11 – 24
3. Classification of Elements and Periodicity in 25 – 33
Properties
4. Chemical Bonding and Molecular Structure 34 – 52
5. Thermodynamics 53 – 64
6. Equilibrium 65 - 76
7. Redox Reactions 77 – 83
8. Organic Chemistry - Some Basic Principles and 84 – 103
Techniques
9. Hydrocarbons 104 – 121
+1 Chemistry Notes for 2024 – 25 – by ANIL KUMAR K L, PHSS VANDIPERIYAR, IDUKKI Page 1
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1. SOME BASIC CONCEPTS OF CHEMISTRY
Chemistry is the branch of Science that deals with the preparation, properties,
structure and reactions of material substances.
Some important branches of Chemistry are:
1. Inorganic Chemistry
2. Organic Chemistry
3. Physical Chemistry
4. Analytical Chemistry
5. Polymer Chemistry
6. Biochemistry
7. Medicinal Chemistry
8. Industrial Chemistry
9. Hydrochemistry
10. Electrochemistry
11. Green Chemistry etc.
Matter: Matter is anything that occupies space and has a definite mass. Based on the physical state we
can divide matter into different categories.
1. Solid state
2. Liquid state
3. Gaseous state
4. Plasma state
5. Bose-Einstein condensate
6. Fermionic condensate
7. Quark-Gluon Plasma
In earth crust, matter mainly exists in three physical states – solid state, liquid state and gaseous
state.
In solids, the particles are orderly arranged and they are very close to each other. The particles
cannot move freely. So solids have definite shape and definite volume.
In liquids, the particles are close to each other but they can move around. So, liquids have definite
volume but do not have definite shape.
In gases, the particles are far apart as compared to those present in solid or liquid state and their
movement is easy and fast. So they do not have definite shape and volume. They take the shape of the
container in which they are placed. Also they occupy the complete space of the container in which they
are placed.
The three states of matter are interconvertible by changing the conditions of temperature and
pressure.
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Classification of matter
Based on the chemical composition, matter can be divided into two categories – pure substances and
mixtures.
Pure substances contain only one type of particles. E.g. Sodium (Na), Potassium (K), Hydrogen
(H), Oxygen (O), Helium (He), carbon dioxide (CO2), water (H2O), ammonia (NH3), cane sugar (C12H22O11)
etc.
Pure substances are classified into two – elements and compounds.
Elements are pure substances which contain only one type of atom. The term element was first
introduced by Robert Boyle, the father of ancient Chemistry. Now there are 118 elements starting from
hydrogen (1H) and ending in Oganesson (118Og). Some elements exist as monoatomic, some are diatomic
and some others are polyatomic. E.g. all metals (Sodium, Potassium, Calcium etc) and noble gases
(Helium, Neon etc.) are monoatomic. Hydrogen, Nitrogen, Oxygen etc are diatomic. Phosphorus (P4) and
Sulphur (S8) are polyatomic.
Compounds are pure substances which contain more than one type of atoms. They are formed
by the combination of two or more atoms of different elements in a definite ratio. Their constituents
cannot be separated by physical methods, but they can be separated by chemical methods.
E.g. CO2, H2O, NH3, H2SO4 etc.
Mixtures contain more than one type of particles. The components of a mixture can be
separated by using physical methods like filtration, crystallisation, distillation etc.
E.g. all types of solutions, gold ornaments, sea water, muddy water, air etc.
There are two types of mixtures – homogeneous and heterogeneous mixtures.
Mixtures having uniform composition throughout are called homogeneous mixtures. Here the
components are completely mixed with each other. E.g. all type of solutions, air etc.
Mixtures having different compositions at different parts are called heterogeneous mixtures.
E.g. sea water, soil. Muddy water etc.
Physical and chemical properties
The properties or characteristics of matter can be classified into two types — physical properties
and chemical properties.
Properties which can be measured or observed without changing the composition or identity of the
substance are called physical properties. Measurement of physical properties does not require the
occurrence of a chemical change.
E.g. colour, odour, melting point, boiling point, density, mass etc.
Properties which can be measured only with the occurrence of a chemical change are called chemical
properties. E.g. composition, combustibility, reactivity with acids and bases, etc.
Measurement of physical properties
Any quantitative observation or measurement is represented by a number followed by units in
which it is measured. Earlier, two different systems of measurement were used: the English System and
the Metric System.
Now a days, a common standard system known as International System of Units (SI) is used. This
system has seven base units and they are length, mass, time, electric current, thermodynamic
temperature, amount of substance and luminous intensity. Their SI units are as follows:
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Physical Quantity SI unit & its symbol Electric current ampere (A)
Length metre (m) Thermodynamic temperature kelvin (K)
Mass kilogram (kg) Amount of substance mole (mol)
Time second (s) Luminous intensity candela (cd)
Mass and Weight
Mass is the amount of matter present in a body. It is a constant quantity. Its SI unit is kilogram (kg).
Weight is the gravitational force acting on a body. It is a variable quantity. i.e. it changes with place. Its SI
unit is newton (N).
Volume (V)
It is the amount of space occupied by a body. Its SI unit is m3. In Chemistry, smaller volumes are used.
Hence, volume is often denoted in cm3, dm3, mL, L etc.
1 m3 = 106 cm3 1 L = 103 cm3 (mL) 1cm3 = 1 mL
1 dm3 = 103 cm3 1 dm3 = 1 L
Density (d)
It is the amount of mass per unit volume.
i.e. density = mass/volume. Its SI unit is kg/m3. But it is commonly expressed in g/cm3.
Temperature (T)
It is the degree of hotness or coldness of a body. It is commonly expressed in degree celsius ( 0C). Other
units are degree fahrenheit (0F), kelvin (K) etc. Its SI unit is kelvin (K).
Degree celsius and degree fahrenheit are related as:
0F
9 0
= ( C) + 32
5
Degree celsius and kelvin are related as:
K = 0C + 273.15 OR, K = 0C + 273
Precision and Accuracy
Precision refers to the closeness of various measurements for the same quantity. But,
accuracy is the agreement of a particular value to the true value of the result.
Scientific Notation
It is an exponential notation in which a number is represented in the form N × 10n, where n is an
exponent having positive or negative values and N is a number (called digit term) which varies between
1.000... and 9.999.....
While writing scientific notation, the value of the exponent ‘n’ becomes positive, when the
decimal is shifted to left and it becomes negative, when the decimal is shifted to right.
E.g. the scientific notation of 368.9 is 3.689 x 102 and that of 0.000563 is 5.63 x 10-4.
Significant Figures
Every experimental measurement has some amount of uncertainty associated with it. The
uncertainty in the experimental or the calculated values is indicated by mentioning the number of
significant figures. Significant figures are meaningful digits which are known with certainty. The
uncertainty is indicated by writing the certain digits and the last uncertain digit.
There are certain rules for determining the number of significant figures. These are:
1. All non-zero digits are significant. For example in 285 cm, there are three significant figures and
in 0.25 mL, there are two significant figures.
2. Zeros preceding to first non-zero digit are not significant. Such zero indicates the position of the
decimal point. Thus, 0.03 has one significant figure and 0.0052 has two significant figures.
3. Zeros between two non-zero digits are significant. Thus, 2.005 has four significant figures.
+1 Chemistry Notes for 2024 – 25 – by ANIL KUMAR K L, PHSS VANDIPERIYAR, IDUKKI Page 4
CONTENTS
No. Unit Page No.
1. Some Basic Concepts of Chemistry 2 – 10
2. Structure of Atom 11 – 24
3. Classification of Elements and Periodicity in 25 – 33
Properties
4. Chemical Bonding and Molecular Structure 34 – 52
5. Thermodynamics 53 – 64
6. Equilibrium 65 - 76
7. Redox Reactions 77 – 83
8. Organic Chemistry - Some Basic Principles and 84 – 103
Techniques
9. Hydrocarbons 104 – 121
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1. SOME BASIC CONCEPTS OF CHEMISTRY
Chemistry is the branch of Science that deals with the preparation, properties,
structure and reactions of material substances.
Some important branches of Chemistry are:
1. Inorganic Chemistry
2. Organic Chemistry
3. Physical Chemistry
4. Analytical Chemistry
5. Polymer Chemistry
6. Biochemistry
7. Medicinal Chemistry
8. Industrial Chemistry
9. Hydrochemistry
10. Electrochemistry
11. Green Chemistry etc.
Matter: Matter is anything that occupies space and has a definite mass. Based on the physical state we
can divide matter into different categories.
1. Solid state
2. Liquid state
3. Gaseous state
4. Plasma state
5. Bose-Einstein condensate
6. Fermionic condensate
7. Quark-Gluon Plasma
In earth crust, matter mainly exists in three physical states – solid state, liquid state and gaseous
state.
In solids, the particles are orderly arranged and they are very close to each other. The particles
cannot move freely. So solids have definite shape and definite volume.
In liquids, the particles are close to each other but they can move around. So, liquids have definite
volume but do not have definite shape.
In gases, the particles are far apart as compared to those present in solid or liquid state and their
movement is easy and fast. So they do not have definite shape and volume. They take the shape of the
container in which they are placed. Also they occupy the complete space of the container in which they
are placed.
The three states of matter are interconvertible by changing the conditions of temperature and
pressure.
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Classification of matter
Based on the chemical composition, matter can be divided into two categories – pure substances and
mixtures.
Pure substances contain only one type of particles. E.g. Sodium (Na), Potassium (K), Hydrogen
(H), Oxygen (O), Helium (He), carbon dioxide (CO2), water (H2O), ammonia (NH3), cane sugar (C12H22O11)
etc.
Pure substances are classified into two – elements and compounds.
Elements are pure substances which contain only one type of atom. The term element was first
introduced by Robert Boyle, the father of ancient Chemistry. Now there are 118 elements starting from
hydrogen (1H) and ending in Oganesson (118Og). Some elements exist as monoatomic, some are diatomic
and some others are polyatomic. E.g. all metals (Sodium, Potassium, Calcium etc) and noble gases
(Helium, Neon etc.) are monoatomic. Hydrogen, Nitrogen, Oxygen etc are diatomic. Phosphorus (P4) and
Sulphur (S8) are polyatomic.
Compounds are pure substances which contain more than one type of atoms. They are formed
by the combination of two or more atoms of different elements in a definite ratio. Their constituents
cannot be separated by physical methods, but they can be separated by chemical methods.
E.g. CO2, H2O, NH3, H2SO4 etc.
Mixtures contain more than one type of particles. The components of a mixture can be
separated by using physical methods like filtration, crystallisation, distillation etc.
E.g. all types of solutions, gold ornaments, sea water, muddy water, air etc.
There are two types of mixtures – homogeneous and heterogeneous mixtures.
Mixtures having uniform composition throughout are called homogeneous mixtures. Here the
components are completely mixed with each other. E.g. all type of solutions, air etc.
Mixtures having different compositions at different parts are called heterogeneous mixtures.
E.g. sea water, soil. Muddy water etc.
Physical and chemical properties
The properties or characteristics of matter can be classified into two types — physical properties
and chemical properties.
Properties which can be measured or observed without changing the composition or identity of the
substance are called physical properties. Measurement of physical properties does not require the
occurrence of a chemical change.
E.g. colour, odour, melting point, boiling point, density, mass etc.
Properties which can be measured only with the occurrence of a chemical change are called chemical
properties. E.g. composition, combustibility, reactivity with acids and bases, etc.
Measurement of physical properties
Any quantitative observation or measurement is represented by a number followed by units in
which it is measured. Earlier, two different systems of measurement were used: the English System and
the Metric System.
Now a days, a common standard system known as International System of Units (SI) is used. This
system has seven base units and they are length, mass, time, electric current, thermodynamic
temperature, amount of substance and luminous intensity. Their SI units are as follows:
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Physical Quantity SI unit & its symbol Electric current ampere (A)
Length metre (m) Thermodynamic temperature kelvin (K)
Mass kilogram (kg) Amount of substance mole (mol)
Time second (s) Luminous intensity candela (cd)
Mass and Weight
Mass is the amount of matter present in a body. It is a constant quantity. Its SI unit is kilogram (kg).
Weight is the gravitational force acting on a body. It is a variable quantity. i.e. it changes with place. Its SI
unit is newton (N).
Volume (V)
It is the amount of space occupied by a body. Its SI unit is m3. In Chemistry, smaller volumes are used.
Hence, volume is often denoted in cm3, dm3, mL, L etc.
1 m3 = 106 cm3 1 L = 103 cm3 (mL) 1cm3 = 1 mL
1 dm3 = 103 cm3 1 dm3 = 1 L
Density (d)
It is the amount of mass per unit volume.
i.e. density = mass/volume. Its SI unit is kg/m3. But it is commonly expressed in g/cm3.
Temperature (T)
It is the degree of hotness or coldness of a body. It is commonly expressed in degree celsius ( 0C). Other
units are degree fahrenheit (0F), kelvin (K) etc. Its SI unit is kelvin (K).
Degree celsius and degree fahrenheit are related as:
0F
9 0
= ( C) + 32
5
Degree celsius and kelvin are related as:
K = 0C + 273.15 OR, K = 0C + 273
Precision and Accuracy
Precision refers to the closeness of various measurements for the same quantity. But,
accuracy is the agreement of a particular value to the true value of the result.
Scientific Notation
It is an exponential notation in which a number is represented in the form N × 10n, where n is an
exponent having positive or negative values and N is a number (called digit term) which varies between
1.000... and 9.999.....
While writing scientific notation, the value of the exponent ‘n’ becomes positive, when the
decimal is shifted to left and it becomes negative, when the decimal is shifted to right.
E.g. the scientific notation of 368.9 is 3.689 x 102 and that of 0.000563 is 5.63 x 10-4.
Significant Figures
Every experimental measurement has some amount of uncertainty associated with it. The
uncertainty in the experimental or the calculated values is indicated by mentioning the number of
significant figures. Significant figures are meaningful digits which are known with certainty. The
uncertainty is indicated by writing the certain digits and the last uncertain digit.
There are certain rules for determining the number of significant figures. These are:
1. All non-zero digits are significant. For example in 285 cm, there are three significant figures and
in 0.25 mL, there are two significant figures.
2. Zeros preceding to first non-zero digit are not significant. Such zero indicates the position of the
decimal point. Thus, 0.03 has one significant figure and 0.0052 has two significant figures.
3. Zeros between two non-zero digits are significant. Thus, 2.005 has four significant figures.
+1 Chemistry Notes for 2024 – 25 – by ANIL KUMAR K L, PHSS VANDIPERIYAR, IDUKKI Page 4
