• A form of matter in which 2 or more substances
are present in any proportion
• Homogenous or Heterogeneous
Eg. Kerosene, salt solution Sand+water, Uniform
in its composition salt+iron powder
and properties. Different comp
Characteristics of Mixtures –
1. 2 or more subs in any proportion
2. Shows properties of all constituents
3. No energy is absorbed or evolved to make mix
4. Solutions are homo, rest mix are hetero
5. Components can be separated by simple
An element is the simplest form of matter which
cannot be split into simpler substances by any
chemical or physical method. (Antonie Laurent
Element is composed of atoms of the same kind
115 elements – 92 natural and 23 man-made
On basis of phy and chem properties elements r
classified into Metals eg. gold, silver, copper
Non-metals eg. hydrogen,oxygen,nitrogen
Metalloids eg. Boron, silicon, germanium.
A compound is made up of 2 or more elements
combined chemically in a definite proportion by
All compounds r formed as a result of chemical
reaction hence called chemical compounds
Eg. Water is a compound made of hydrogen and
oxygen combined in the ratio of 2:1 by volume.
• Except solutions all mix
• Components r in any
• Properties of
properties of mix
• Can be separated by
simple physical method
• No energy is evolved or
• Always homogeneous
• Components r in fixed
• Property of compound
is diff than components
• Cannot be separated by
simple phy method,
need chem method to
• Involves evolution or
absorption of energy
Types of Mixtures
Solutions Suspensions Colloids
A homogeneous mixture of 2 or more substances is
The substance that is dissolved to obtain a solution
is called a solute.
The substance in which the solute is dissolved to
obtain a solution is called the solvent.
In general the component present in larger amount
in the solution is the solvent and the component
that is present in smaller amount in solution is
called the solute.
Eg. of solution
• Sugar in water ( liquid + solid )
• Ethyl alcohol in water ( liquid + liquid )
• Carbon-dioxide and water ( liquid + gas )
• Brass – 70% copper + 305 zinc ( solid +solid )
• Ornaments- gold + copper or silver ( “ )
Solutions in which water is the solvent is called
the Aqueous solutions. (salt solution)
Solutions obtained by dissolving solute in any
other solvent than water is called Nonaqueous
Concentration of solution
The quantity of solute dissolved in the given
mass or volume of the solvent is called the
concentration of the solution.
Mass % of solute
= mass of solute/mass of solution X 100
Solve – To make a saturated solution, 36g of
sodium chloride is dissolved in 100g of water.
Find its concentration.
Conc = M of NaCl/M of solution X 100
= 36/36 + 100 X 100
= 36/136 X 100 = 26.5 %
A suspension is a heterogeneous mixture in which
very fine particles of solid are dispersed in any
medium. The fine particles remain suspended in the
medium. Eg. Muddy water, chalk + water, smoke
• Particles are visible to eye or under simple
• Particles have tendency to settle down
(sedimentation). But fine particles remain
• Large particles can be separated by filtration.
A heterogeneous mixture in which very fine particles
which can be observed only under powerful microscope
are dispersed in a continuous medium is called a colloid
Eg. Milk, blood, jelly, gum, fog
• particle size is btn 1 to 100nm. 1nm=1/1000000000m
• Colloids are unstable. Particles tend to come together
• It shows Brownian Movement. (zig-zag)
• Tyndall effect – the scattering of light by the particles in
• Under electric current colloidal particles move to +ve
electrode. This is Electrophoresis.
Application of Colloids
• In our food. Eg milk, starch, proteins, jelly
• In medicines. Eg calcium and silver is used in
oral medicines and ointments.
• Raw natural rubber and clay is colloidal in
• Deltas at the sea are result of precipitation of
colloidal clay in the river water.
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