XI Chemistry New Book Concise Notes 2025
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O-Level MCQs Test on Chemical Bonding Set II (Past Papers)
O-Level MCQs Test on Chemical Bonding Set II (Past Papers)
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Chemistry and its Branches
Definition of Chemistry
Why does a
cake rise in the oven?
What are
fireworks made from?
How does
my stomach digest food?
How does
gasoline make an engine run?
What is
the proper way to describe hot and cold?
What
creates the shape of a snowflake?
Why does
iron rust?
How can
soot and diamond be so different in appearance yet so chemically similar?
What makes
propane such an efficient, clean-burning fuel?
These
questions and many more are answered with chemistry. Chemistry has the
power to explain innumerable phenomena in the world, from the ordinary to the bizarre.
Understanding chemistry is the key to understanding the world as we know it. Chemistry
is the study of the make-up of all things and how they behave.
“Chemistry is the branch of science which
deals with the study of composition,
structure, properties (physical and chemical) and transformation of matter along with the chemical changes
that occur in it. It involves the study of physical and chemical changes that matter undergoes and the energy changes accompanying these changes and the laws
and principles governing these
changes.”
OR
Chemistry is the scientific study of matter and its interactions with other
matter and energy. Chemistry deals with chemical elements
and compounds, which consist of atoms and molecules, and the
reactions between them. Chemistry examines the
materials of the universe and changes that these materials undergo
Everything
we hear, see, smell, taste, and touch involves chemistry and chemicals
(matter). And hearing, seeing, tasting, and touching all involves intricate
series of chemical reactions and interactions in our body. With such an
enormous range of topics, it is essential to know about chemistry at some level
to understand the world around us.
Chemistry
as a Central Science
Chemistry
is sometimes called “the central science,” because it bridges physics with
other natural sciences, such as geology and biology.
Matter
Matter; anything
having mass and volume
Mass; the quantity of matter
contained in a body
Volume; space
occupied by body (quantification of how much space an object occupies)
Space; the free area between
two material objects
Everything
that is anything is matter. Matter is defined as anything that has mass and takes up space. You are
matter; trees, houses, rocks, water and even the air you breathe are matter.
Not everything that is a known is matter, however. Time, dreams, heat or light
are not matter. They do not have any mass and they do not take up space. They
are not made of matter.
Origin of Word Chemistry
The word chemistry is derived from the word “Kheem”, an old
name of Egypt due to black
colour of
Egyptian soil.
But some experts believed that the word chemistry came from
the word “Chyma” meaning melt or
cast.
As the time passed on the word changed to Al-kimyain in Arabic and then to “chemistry” in English.
Branches of Chemistry
The
complete understanding and mastery over vast scientific knowledge is almost
impossible. To facilitate the study of science, it has been subdivided into different disciplines.
Chemistry, being a vast discipline of science has also been divided into a
number of branches to facilitate its study. As our universe is an integrated
unit so is its knowledge. There are no clear-cut boundaries between these
branches. Chemists have made these divisions for the sake of their own
convenience.
All these
branches of chemistry must deal with each other one way or another. If they did
not work in unison it would be impossible for these chemistries to perform the
functions we need for experiments. Thus all these branches of chemistry overlap
each other.
For
example, one would not be able to measure the change in an organic or inorganic
substance without knowing how to use analytical chemistry or without some
proficiency in analytical chemistry. Chemistry can be divided into branches
according to either the substances studied or the types of study conducted. The
primary division of the first type is inorganic chemistry and organic chemistry
and divisions of the second type are physical chemistry and analytical
chemistry.
Summary of Branches of Chemistry
The chemistry has been divided into following main branches:
1. Physical chemistry
is the branch of chemistry which deals with relationship
between composition and physical properties of matter with the changes in them.
2. It is the branch of chemistry that deals
with the physical properties of substances and their dependence on chemical bonding.
3. It deals
with the forces and laws and principles governing the combination of atoms and molecules especially concerned with energy changes in physical
and chemical processes.
4. The
branch of Chemistry that deals with
laws and theories to understand the structure and changes of matter is called Physical Chemistry
5. It
is concerned with structure of atoms and molecules, behaviour of gases, liquids and
solids, effect of
temperature or radiation on matter etc.
6. Important areas of study of physical chemistry include chemical thermodynamics, chemical kinetics, quantum chemistry, statistical mechanics, ionic equilibria, electrochemistry,
and spectroscopy.
Inorganic
Chemistry
It is that branch of chemistry that
deals with the study of all elements and their compounds generally obtained from non-living or mineral origin except
carbon-hydrogen (hydrocarbons) compounds and their derivatives (organic compounds). It is applicable in
all areas of chemical industry such as glass, cement, ceramics and metallurgy.
Inorganic
chemistry is concerned with the properties and behaviour of all elements in the
periodic table and inorganic compounds, which include metals, minerals, acids, bases, salts, and
organometallic compounds.
Organic Chemistry
1. It is the branch of chemistry
which deals with hydrocarbons and their derivatives.
CH4
(methane, HC) ====== CH3Cl (chloromethane; Derivative of methane)
C2H6
(Ethane, HC) ====== C2H5OH (ethanol; Derivative of ethane)
C2H4
(Ethene)======
C2H3Cl (Chloroethene; Derivative of ethene)
Ethyne
(C2H2)
Benzene (C6H6)
Glucose (C6H12O6)
Sugar (C12H22O11)
Ethyl alcohol (C2H5OH)
Acetic acid (CH3COOH)
Chloroform (CHCl3)
2. Organic chemistry is the study of structure, properties, composition, reactions, and
preparation of carbon-containing
compounds generally
obtained from living organisms.
Organic chemistry is the study of
structure, properties, composition, reactions, and preparation of carbon-containing compounds generally obtained from living
organisms, which include hydrocarbons and their
derivatives with the exception of carbon oxides (CO, CO2,), metal carbonates (CO32−), bicarbonates (HCO3−), cyanides (CN−), thoicyantes (CNS−), cyanates (CNO−) and carbides (C4−).
3. The gasoline, plastics, detergents,
dyes, food additives, natural gas, and medicines are studied in the organic chemistry.
Biochemistry
It is the branch of chemistry that deals
with the compounds
of living organisms i.e.
plants and animals (such as DNA, proteins, carbohydrates, lipids etc.) and their reactions (metabolism)
and synthesis in living organisms (i.e. in plants and animals).
Biochemistry is the backbone of medical science. This
branch is useful in medicine, agriculture and food
science.
Biochemistry helps us to understand how
living things obtain energy from food. It tells that how disorder or deficiency
of these biomolecules causes diseases.
Industrial
Chemistry
It is the branch of chemistry that deals with the study of different chemical processes involved for commercial manufacturing
of synthetic products (like cements, glass,
cement, paper, fertilizers, medicines, plastics, paints, soaps, detergents,
soda ash, caustic soda etc.).
It is the application of chemical
knowledge in technology and industry for preparation of industrial products on large scale.
Industrial chemistry helps us in the manufacturing of the industrial products
and their uses.
The branch of Chemistry that deals
with the methods and use of technology in the large-scale production of useful
substances is called industrial chemistry.
Nuclear chemistry
It deals with the changes occurring in the nuclei of atoms accompanied by emission of radiation. It also deals with the characteristics of radioactivity or radioactive processes both natural and
artificial, nuclear processes and atomic energy generated there.
Radioactive elements are widely used in
medicine as diagnostic tools and as a means of treatment, especially for
cancer, preservation of food and generation of electric power through nuclear
power reactors.
Analytical
Chemistry
1.Analytical chemistry is the branch of
chemistry which deals with separation and
analysis of kind, quality and
quantity of various components in given
substance.
2. It deals with the methods and techniques used
to determine the kind and quantity of various components
in a given substance.
3. Analytical chemistry seeks to
determine the exact chemical compositions of substances. It used in chromatography,
electrophoresis and spectroscopy.
4. Analytical chemistry is concerned with the qualitative and quantitative analysis of different substances.
5. The branch of Chemistry that deals with the methods and
instruments for determining the exact chemical
composition of matter (substances) is called Analytical Chemistry
6. It
used in chromatography, electrophoresis and spectroscopy.
Chemistry equations provide a powerful symbolic notation to express qualitative and
quantitative details of chemical transformations i.e. chemical change. The
calculation which deals with Stoichiometry (means 'to measure an element'), the
fundamental concept is that the chemical equation, if interpreted correctly, is
basis for all such calculations.
Types
Analytical
chemistry can be split into two main types, qualitative and quantitative:
(1) Qualitative analysis, It involves identification of a substance i.e. composition of chemical species
(i) Qualitative inorganic analysis is used to identify the presence of a given element or inorganic compound in a sample.
(ii) Qualitative organic analysis is used to detect the presence of a given functional group or organic compound in a sample.
(2) Quantitative analysis
determines the amount of each component present in a sample.
Environmental
Chemistry
It is the study of the interaction
of various chemical materials and their effects on human or animals and plants
environment.
Pollution, personal hygiene and health hazards are important aspects of environmental chemistry.
The branch of Chemistry that deals with the chemicals and
toxic substances that pollute the environment and their adverse effects on
human beings is called environmental chemistry
Medicinal Chemistry
It deals with synthetic organic chemistry, pharmacology and various biological
specialties.
The medicinal chemistry is used in
synthesis of chemicals, bioactive molecules
(Drugs) and pharmaceutical agents.
Quantum Chemistry/ molecular
quantum mechanics
1. It deals with application of quantum mechanics and experiments of physical models in chemical system at the atomic
level.
2. It is also called molecular quantum mechanics.
3. It is a branch of physical chemistry deals with
the behaviour of matter and light on the atomic and
subatomic scale. It attempts
to describe and account for the properties of molecules and atoms and their constituents—electrons, protons,
neutrons, and other more esoteric particles such as quarks and gluons
4. One of the
most important principles underlying quantum chemistry is that of wave-particle
duality. Quantum objects
have both particle-like properties (such as mass, charge, and energy)
and wave-like properties (such as
wavelength and frequency). We can see this when we observe light traveling through a prism.
5. Chemists rely heavily on spectroscopy through
which information regarding the quantization of energy on
a molecular scale can be obtained. Common methods are infra-red (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and scanning probe microscopy. Quantum
chemistry may be applied to the
prediction and verification of spectroscopic data as well as other experimental data.
Green Chemistry/sustainable
chemistry
1. Green
chemistry can be defined as the practice of chemical science and
manufacturing in a manner that
is sustainable, safe, and non-polluting and that consumes
minimum amounts of materials and energy while producing little or no waste material. In
other words, Green chemistry is the study of designing
of chemical products and processes that reduce or eliminate the use or
generation of hazardous
substances. Green chemistry applies across the life cycle
of a chemical product, including its design,
manufacture, use, and ultimate disposal.
2. Green
chemistry is the branch of chemistry that deals with the design and
optimization of processes and chemical
products in order to lower or remove completely, the production and use of toxic substances. Green
chemistry is not the same as environmental chemistry. It focuses
on the environmental
impact of chemistry and the development of sustainable
practices that are environment-friendly (such as a
reduction in the consumption of non-renewable resources and strategies to control environmental
pollution).
3. It deals with study of processes and designing products, which are composed of less
hazardous substances.
4. The main
purpose of this branch is to use waste materials efficiently and improvement
of energy efficiency in chemical
industry.
5. Safer chemical (polyphenylsulfon), less
hazardous chemical (poly carbons) and safer biodegradable Green solvents are examples
of green chemistry.
Polyphenylsulfone (PPSU, PPSF)
Polyphenylsulfone (PPSU, PPSF) is an amorphous,
heat-resistant and transparent high-performance thermoplastic synthesized
by nucleophilic aromatic substitution between difluorodiphenyl sulfone and the sodium
salt of 4,4-dyhydroxybiphenyl with elimination of sodium fluoride.
The biphenylene ether unit of PPSU markedly increases the impact strength and
reduces the notch sensitivity, resulting in high notched (Izod) impact values
which exceeds those of other polysulfones (PSU, PES). It also
contributes to ease of melt fabrication.
Commercially important polysulfones
are prepared by condensation of 4,4'-bis(chlorophenyl)sulfone with various bisphenols. Two
bisphenols for this application are bisphenol A (the polymer
being called PSF) and 4,4'-bis(4-hydroxyphenyl)sulfone (the polymer
being called PES).
PPSU is the highest performing
polysulfone. It is known for its high toughness, high flexural and
tensile strength, excellent hydrolytic stability and good resistance
to chemicals and heat. Compared to the two other polyethersulfones PSU and PES, it has superior
mechanical properties, but it is also more expensive, and thus,
less widely used. It also has the best chemical resistance of all
polyethersulfones. For example, it is highly resistant to aqueous mineral
acids, bases, and oxidizing agents and most solvents. However, aromatic solvents
and oxygenated solvents, such as ketones and ethers, might cause some stress
cracking.
Applications of Polyphenylsulfone
(PPSU, PPSF)
PPSF is a moldable plastic often used
in rapid prototyping and rapid manufacturing (direct digital manufacturing)
applications. Polyphenylsulfone is heat and chemical-resistant suited for automotive,
aerospace, and plumbing applications.
PPSU is often an excellent choice for
components that are exposed to high temperatures and corrosive media because it
has exceptional chemical resistance. Examples include pipe
fittings, battery containers, medical device parts, and sterilizable
products for health care and nursing. Polyphenylsulfone is also used in the
automotive and aerospace industries for
applications where superior thermal and mechanical properties relative to
conventional resins are required.
Polycarbonates (PC)
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate
groups in their chemical structures. Polycarbonates used in engineering
are strong, tough materials, and some grades are optically transparent. They are
easily worked, molded, and thermoformed. Because of these properties, polycarbonates
find many applications.
Products made from polycarbonate can
contain the precursor monomer bisphenol A (BPA).
Among the uses of the polycarbonates
and their blends are:
▶ medical (for
example, for dialysis housing and spectacle lenses)
▶ electro-electronic (for example, sockets, lamp covers,
▶fuse-boxes, computer and television housings)
▶ construction (for
example, stadium roofs, signs, skylights)
▶ optical storage (CDs,
DVD, HD-DVDs)
▶cars (interior
lighting and headlamps, sunroofs, side windows, radiators, grilles, bumpers)
▶ packaging (large
water bottles)
Green Solvents
Green solvents are ecological-
or environmentally-friendly, biodegradable, and
sustainable solvents or bio-solvents, which are derived from the processing
of agricultural crops.
The use of petrochemical solvents is
the key to the majority of chemical processes but not without severe
implications on the environment. Green solvents were developed as a more environmentally
friendly alternative to petrochemical solvents.
Examples of Green Solvents
Ethyl lactate, for example,
is a green solvent derived from processing corn. Ethyl lactate is the ester of
lactic acid. Lactate ester solvents are
commonly used solvents in the paints and coatings
industry and have numerous attractive advantages including being 100%
biodegradable, easy to recycle, noncorrosive, non-carcinogenic, and
non-ozone-depleting. Ethyl lactate is a particularly attractive solvent for the
coatings industry as a result of its high solvency power, high boiling point,
low vapor
pressure, and low surface
tension. It is a desirable coating for wood, polystyrene, and metals
and also acts as a very effective paint
stripper and graffiti remover. Ethyl lactate has replaced solvents such as
toluene, acetone, and xylene,
resulting in a much safer workplace. Other applications of ethyl lactate
include being an excellent cleaner for the polyurethane industry.
Ethyl lactate has a high solvency power, which means it is able to dissolve a
wide range of polyurethane resins. The excellent cleaning power of ethyl
lactate also means it can be used to clean a variety of metal surfaces,
efficiently removing greases, oils, adhesives, and solid fuels. The use of
ethyl lactate is highly valuable, as it has eliminated the use of chlorinated
solvents.
There are many types of green
solvents like ionic liquids, supercritical fluids, water, and supercritical
water. These green solvents are way much eco-friendly, less toxic, less
hazardous than traditional volatile organic compounds (VOCs).
Aim of GC
The goal of green chemistry (GC) is
the design (or redesign) of products and manufacturing processes to reduce
their impact on human health and the
environment. Fundamental to the GC concept is the idea of sustainability –
reducing environmental impacts and conserving natural resources for future
generations. It aims to improve the efficiency with which natural resources are
used for chemical products.
GC is used
▶ To prevent
pollution at the molecular level
▶ As a philosophy that applies to all areas
of chemistry, not a single discipline of chemistry
▶ To apply innovative scientific solutions to real-world environmental
problems
▶ In resulting in source
reduction because it prevents the generation of pollution
▶ To reduce the negative impacts of chemical products and processes
on human health and the environment
▶ To lessen and sometimes eliminates hazard from
existing products and processes
▶ To design chemical products and processes to reduce
their intrinsic hazards
The 12 Key Principles of Green Chemistry
▶ Prevention of waste
▶ Atom economy
▶ Avoiding the
generation of hazardous chemicals
▶ The design of
safe chemicals
▶ Design of
safe auxiliaries and solvents
▶ Energy
efficiency
▶ Incorporation
of renewable feedstock
▶ Reduction in
the generation of derivatives
▶ Incorporation
of Catalysis
▶ Designing the
chemicals for degradation
Incorporating real-time analysis
Incorporation of safe chemistry for the prevention of accidents
Prevention of waste:
Preventing the formation of waste products is always preferable to
the clean-up of the waste once it is generated.
Atom economy:
The synthetic processes and methods that are devices through green
chemistry must always try to maximise the consumption and incorporation of all
the raw materials into the final product. This must strictly be followed in
order to minimise the waste generated by any process.
Avoiding the generation of hazardous chemicals:
Reactions and processes that involve the synthesis of certain toxic
substances that pose hazards to human health must be optimised in order to
prevent the generation of such substances.
The design of safe chemicals
During the design of chemical products that accomplish a specific
function, care must be taken to make the chemical as non-toxic to humans and
the environment as possible.
Design of safe auxiliaries and solvents
The use of auxiliaries in processes must be avoided to the largest
possible extent. Even in the circumstances where they absolutely need to be
employed, they must be optimized to be as non-hazardous as possible.
Energy efficiency
The amount of energy consumed by the process must be minimized to
the maximum possible extent.
Incorporation of renewable feedstock
The use of renewable feedstock and renewable raw materials must be
preferred over the use of non-renewable ones.
Reduction in the generation of derivatives
The unnecessary use of derivatives must be minimalized since they
tend to require the use of additional reagents and chemicals, resulting in the
generation of excess waste.
Incorporation of Catalysis
In order to reduce the energy requirements of the chemical
reactions in the process, the use of chemical catalysts and catalytic reagents
must be advocated.
Designing the chemicals for degradation
When designing a chemical product in order to serve a specific
function, care must be taken during the design process to make sure that the
chemical is not an environmental pollutant. This can be done by making sure
that the chemical breaks down into non-toxic substances.
Incorporating real-time analysis
Processes and analytical methodologies must be developed to the
point that they can offer real-time data for their monitoring. This can enable
the involved parties to stop or control the process before toxic/dangerous
substances are formed.
Incorporation of safe chemistry for the prevention of accidents
While designing chemical processes, it is important to make sure
that the substances that are used in the processes are safe to use. This can
help prevent certain workplace accidents, such as explosions and fires.
Furthermore, this can help develop a safer environment for the process to take
place in.
Examples of the Impact of Green Chemistry
Use of Green Solvents
Many chemical synthesis reactions
that are carried out on an industrial scale require large amounts of chemical
solvents. Furthermore, these solvents are also used industrially for degreasing
and cleaning purposes. However, many traditional solvents that have been used
for such purposes in the past are known to be toxic to human beings. Some such
solvents are also known to be chlorinated.
The advancement of green chemistry
has brought many alternatives to these toxic solvents. The green solvents that
are coming up as alternatives are known to be derived from renewable sources
and are also known to be biodegradable. Thus, green chemistry has great
potential to lower the toxicity of certain industrial environments by
developing safer alternatives.
Development of Specialized Synthetic Techniques
The development of specialized
synthetic techniques can optimize processes in order to make them more
environmentally friendly by making them adhere to the principles of green
chemistry. An important example of such an enhanced synthetic technique is the
development of the olefin metathesis reaction in the field of organic
chemistry. This reaction, developed by Robert Grubbs, Richard Schrock, and Yves
Chauvin, won the Nobel Prize for Chemistry in the year 2005.
Other notable developments brought forward by advancements in
green chemistry include:
The employment
of supercritical carbon dioxide as a green solvent (as an alternative to other
toxic solvents).
Incorporating
the use of hydrogen in enantioselective synthesis reactions (also known as
asymmetric synthesis).
Incorporating aqueous solutions of
hydrogen peroxide (a chemical compound with the formula H2O2)
to drive relatively clean oxidation reactions.
Other notable applications of green
chemistry include supercritical water oxidation (often abbreviated to SCWO),
dry media reactions (also known as solid-state reactions and solvent fewer
reactions), and on water reactions.
Production of Hydrazine
Initially, the most popular method
for the production of hydrazine (an inorganic chemical compound with the
chemical formula N2H4) was the Olin Raschig process,
which involved the use of ammonia and sodium hypochlorite. However, with the
development of green chemistry, a more environment-friendly alternative to this
process was discovered.
In the peroxide process for the
production of hydrazine, ammonia is reacted with hydrogen peroxide. In this
alternate method, water is produced as the only side product. It can also be
noted that the peroxide process does not require any auxiliary extracting
solvents.
Polymeric Chemistry
It deals with the process of polymerization and the products obtained through the process of
polymerization called polymers (such as plastics, synthetic
fibers, papers etc.)
(CH2=CH2) → (– CH2
– CH2 – )n
Vinegar contains 5% acetic acid. Acetic acid (CH3COOH)
is a colourless liquid that has characteristic vinegar like smell. It is used
to flavour food. Various types of studies on this compound can help you to differentiate
between various branches of chemistry.
1. Explanation of its transformation into gaseous state or solid state, applications of laws and theories to understand its structure is physical chemistry.
2. Since this is a carbon compound, its method of
preparations and study of its physical and chemical characteristics is organic chemistry.
3. But the study of its component elements, carbon, hydrogen
and oxygen is inorganic chemistry. This is because
inorganic chemistry deals with elements and their compounds except carbon
compounds.
However, some
carbon compounds such as CO2 , CO, metal carbonates, hydrogen
carbonates and carbides are
studied in inorganic chemistry.
4. The study of chemical reactions that acetic acid undergoes
in the bodies of human beings is biochemistry.
5. Use of technology
and ways to obtain acetic acid on the large scale is industrial chemistry.
6. The study of the effect of radioactive radiations or
neutron on this compound or its component elements is nuclear chemistry.
7. The study of any adverse effects of this compound or the
compounds that are derived from it, on the humans
is environmental chemistry.
8. The method and instruments used to determine its
percentage composition, melting point, boiling point etc. is analytical chemistry.
Identify the branch of chemistry in
each of the following examples:
1. Photosynthesis produces glucose and oxygen from carbon
dioxide and water in presence of chlorophyll and
sunlight.
2. Plantation helps in overcoming greenhouse effect.
3. Haber’s process converts large quantities of hydrogen and
nitrogen into ammonia NH3
4. Ammonia is a colourless gas with pungent irritating odour.
It is highly soluble in water.
5. A chemist performed an experiment to check the percentage
purity of a sample of glucose C6H12O6
6. An analyst determines that NO2 is responsible
for acid rain.
7. Chlorofluorocarbon compounds are responsible for the
depletion of ozone layer.
8. α-particles (He2+) when bombard on nitrogen
atom, a proton is emitted.
Problem Solving strategy:
Concentrate on the basic definition of each branch of
chemistry and identify branch of chemistry in each example.
Solution:
1. Biochemistry, since photosynthesis is a chemical reaction
that occurs in plants (living organism).
2. Environmental chemistry, since greenhouse effect is an
environmental problem.
3. Industrial chemistry, since large scale production of any
substance is the subject of industrial chemistry.
4. Inorganic chemistry, since it deals with properties of
inorganic compounds.
5. Analytical chemistry, since it deals with analysis of a
compound, whether organic or inorganic in nature.
6. Environmental chemistry, since acid rain is an
environmental problem.
7. Environmental chemistry, since depletion of ozone layer is
environmental problem.
8. Nuclear chemistry, since nuclear change can emit protons
Identify the branch of chemistry that
is related to the following information:
1. Hair contain a special class of proteins called keratins,
which are present in nails and wool. Proteins contain
chains of C-atoms.
2. Acetylene is the simplest hydrocarbon that contains carbon-carbon triple bond. Hydrocarbons are the compounds of carbon and hydrogen.
3. White lead is a pigment used by artists for centuries, the
metal Pb in the compound is extracted from its ore,
galena (PbS).
4. Sulphuric acid H2SO4 is extremely corrosive
to skin.
5. Gases can be compressed by applying pressure.
6. Meat, Milk and eggs contain long chains of carbon
compounds.
7. Element radium decays by emitting α-particles and is
converted into another element radon.
8. Calorimeter is a device that measures the amount of heat,
a substance absorbs on heating or emits on cooling.
Importance of Branches of Chemistry
Chemistry plays a vital role in the modern world. It has not
only changed our standard of living but also has improved health conditions.
Every branch of chemistry has its own importance in human life.
1.
Biochemistry is the backbone of medical science.
2.
Industrial chemistry
helps us in manufacturing of industrial products.
3.
Environmental chemistry
tell us that how one can protect its environment from environmental hazards.
4. Analytical chemistry is
important to understand the composition of compounds, quality of products, analysis of biological
samples (urine, blood, milk etc.)
5. Nuclear chemistry gives atomic energy that can
be used in various fields. It also provides us Radioisotopes for the
treatment of many diseases such as cancer.
Importance of Chemistry in daily Life
(Role of Chemistry in Society)
The role of chemistry in daily life is
unavoidable fact.
1. Cooking, eating and digestion of food are purely chemical processes.
2. Construction, cleaning and washing of our homes are dependable on
chemistry.
3. The production of fertilizers, glass, plastic synthetic fiber, polymer,
ceramics, petroleum products, soaps,
and detergents etc. are based on chemistry.
4. The diseases
transmitted through impure drinking water as cholera, typhoid, dysentery, skin
and eye infections can be controlled with the help of chlorine treatment to kill
the pathogenic organism to obtain
pure water.
5. The chlorine is most
important chemical which used commercially to produce more than one thousands
compounds which are used in chemical industry as bleaching agent, disinfectants, solvents, pesticides, refrigerates, PVC and drugs are miracles of chemistry.
Historical Back Ground of Chemistry (Time Chronology of Chemistry)
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XI Chemistry New Book Concise Notes 2025 Download here
