Some Basic Concepts of Chemistry 1 Flashcards
what is matter?
Anything that has mass and occupies space is known as matter
how is the arrangment of particles in three states of matter
Matter exists in 3 states: solid,liquid and gas.
Particles are held very close to each other
in solids in an orderly fashion and there is not
much freedom of movement. In liquids, the
particles are close to each other but they can
move around. However, in gases, the particles
are far apart as compared to those present in
solid or liquid states and their movement is
easy and fast. Because of such arrangement
of particles, different states of matter exhibit different characteristics
what are properties exhibited by the 3 states of matter?
(i) Solids have definite volume and definite
shape.
(ii) Liquids have definite volume but do
not have definite shape. They take the
shape of the container in which they are
placed.
(iii) Gases have neither definite volume nor
definite shape. They completely occupy
the space in the container in which they
are placed.
how to convert states of matter from one form to the other?
These three states of matter are
interconvertible by changing the conditions
of temperature and pressure.
On heating, a solid usually changes to
a liquid, and the liquid on further heating
changes to gas (or vapour). In the reverse
process, a gas on cooling liquifies to the liquid and the liquid on further cooling freezes to the solid.
what are pure substances
When all constituent particles of a
substance are same in chemical nature, it
is said to be a pure substance.
what are characteristics of pure substances?
Pure substances have characteristics
different from mixtures. Constituent particles
of pure substances have fixed composition.
Copper, silver, gold, water and glucose are
some examples of pure substances. Glucose
contains carbon, hydrogen and oxygen in
a fixed ratio and its particles are of same
composition. Hence, like all other pure
substances, glucose has a fixed composition.
Also, its constituents—carbon, hydrogen
and oxygen—cannot be separated by simple
physical methods.
How are pure substances divided?
-elements
-compounds
further into inorganic and organic cpds
what is element?
An element is the simplest form of pure substance. It cannot be further divided into simpler substances by any physical or chemical means.
Particles of an element consist of only one type of atoms.These particles may exist as atoms or
molecules.Sodium, copper, silver,
hydrogen, oxygen, etc., are some examples
of elements. Their all atoms are of one type.
the atoms of different elements are different in nature. explain
the atoms of different elements
are different in nature. Some elements,
such as sodium or copper, contain atoms
as their constituent particles, whereas, in
some others, the constituent particles are
molecules which are formed by two or more
atoms. For example, hydrogen, nitrogen and
oxygen gases consist of molecules, in which
two atoms combine to give their respective
molecules.
what is a compound?
A compound is a pure substance that contain 2 or more elements combined in a fixed proportion by mass.
Moreover, the constituents of a compound
cannot be separated into simpler substances
by physical methods. They can be separated
by chemical methods. Examples of some
compounds are water, ammonia, carbon
dioxide, sugar, etc
how are atoms present in a cpds?
Note that a water molecule comprises
two hydrogen atoms and one oxygen atom.
Similarly, a molecule of carbon dioxide
contains two oxygen atoms combined with
one carbon atom. Thus, the atoms of different elements are present in a compound in a fixed
and definite ratio and this ratio is characteristic
of a particular compound.
the properties
of a compound are different from those of its
constituent elements. explain with ex
the properties
of a compound are different from those of its
constituent elements. For example, hydrogen
and oxygen are gases, whereas, the compound
formed by their combination i.e., water is a
liquid. It is interesting to note that hydrogen
burns with a pop sound and oxygen is a
supporter of combustion, but water is used
as a fire extinguisher.
what are mixtures and their propertieS?
A mixture contains particles of two or
more pure substances which may be present
in it in any ratio. Hence, their composition is
variable. Pure substances forming mixture
are called its components. Many of the
substances present around you are mixtures.
WHat are the types of mictures?
homogeneous and heterogeneous
what are homogenous mixtures?
In a
homogeneous mixture, the components completely mix with each other. This means
particles of components of the mixture are
uniformly distributed throughout the bulk of
the mixture and its composition is uniform
throughout.
Homogenous material has uniform composition and particles of the mixture cannot be distinguishes from each other. It has identical properties throughout. It conssits of only 1 phase.
