Some Basic Concepts of Chemistry 3 Flashcards
where are principle of chemistry applicable?
Principles of chemistry are applicable
in diverse areas, such as weather patterns,
functioning of brain and operation of a
computer, production in chemical industries,
manufacturing fertilisers, alkalis, acids, salts,
dyes, polymers, drugs, soaps, detergents,
metals, alloys, etc., including new material.
what are the ways in which chemistry is used in everyday life?
-Chemistry contributes in a big way to the
national economy.
-It also plays an important
role in meeting human needs for food,
healthcare products and other material
aimed at improving the quality of life.
-This is exemplified by the large-scale production
of a variety of fertilisers, improved variety
of pesticides and insecticides.
-Chemistry provides methods for the isolation of lifesaving drugs from natural sources and makes possible synthesis of such drugs.
Some of these drugs are cisplatin and
taxol, which are effective in cancer therapy.
The drug AZT (Azidothymidine) is used for
helping AIDS patients.
How does chemistry contribute to the development of the nation?
Chemistry contributes to a large extent in
the development and growth of a nation. With
a better understanding of chemical principles
it has now become possible to design and
synthesise new material having specific
magnetic, electric and optical properties. This
has lead to the production of superconducting
ceramics, conducting polymers, optical fibres,
etc. Chemistry has helped in establishing
industries which manufacture utility goods,
like acids, alkalies, dyes, polymesr metals,
etc. These industries contribute in a big way
to the economy of a nation and generate
employment.
how has chem helped reduce environmental problems?
chemistry has helped in
dealing with some of the pressing aspects
of environmental degradation with a fair
degree of success. Safer alternatives to
environmentally hazardous refrigerants,
like CFCs (chlorofluorocarbons), responsible
for ozone depletion in the stratosphere, have
been successfully synthesised.
what are problems tht chemists face?
many big environmental problems continue to
be matters of grave concern to the chemists.
One such problem is the management of the
Green House gases, like methane, carbon
dioxide, etc. Understanding of biochemical
processes, use of enzymes for large-scale
production of chemicals and synthesis of new
exotic material are some of the intellectual
challenges for the future generation of
chemists. A developing country, like India,
needs talented and creative chemists for
accepting such challenges.
What is atomic mass?
The number of times an atom of an element is heavier than 1/12th part of C-12 isotope of carbon.
define amu
amu-atomic mass unit
One atomic mass unit is defined as the mass exactly equal to 1/12th the mass of one atomof c-12 isotope of carbon.
‘amu’ has been replaced by
‘u’, which is known as unified mass.
What is average atomic mass?
Many naturally occurring elements exist
as more than one isotope. When we take
into account the existence of these isotopes
and their relative abundance (per cent
occurrence or their fractional abundance), the average atomic mass of
that element can be computed.
The avg atomic mass is reflected in the periodic table
what is percent occurence
Fractional abundance of an isotope is the fraction of the total number of atoms comprised of that particular isotope.
what is molecular mass?
Molecular mass is the sum of atomic masses
of the elements present in a molecule
what about ionic cpds
Some substances, such as sodium chloride,
do not contain discrete molecules as their
constituent units. In such compounds,
positive (sodium ion) and negative (chloride ion)
entities are arranged in a three-dimensional
structure. One na+ ions is surrounded by 6 Cl- ions and vice versa
what is formula mass?
The formula, such as NaCl, is used to
calculate the formula mass instead of
molecular mass as in the solid state sodium
chloride does not exist as a single entity.
what is one mole?
mole (symbol, mol) was
introduced as seventh base quantity for the
amount of a substance.
The mole, symbol mol, is the SI unit of
amount of substance
1 mole is the amount of substance that contains as many particles or entities as there are atoms in 12g of c-12 isotope of carbon
what is avogadro’s constant
One mole contains
exactly 6.02214076 ×10²³ elementary entities.
This number is the fixed numerical value of
the Avogadro constant, NA, when expressed
in the unit mol–1 and is called the Avogadro
number.
What is molar mass
The mass of one
mole of a substance in grams is called its
molar mass. The molar mass in grams is
numerically equal to atomic/molecular/
formula mass in u.
