Hg
Name: Class 9
___________________________________________________________________________________________________________________________________
___________________________________________________________________________________________________________________________________
The Hg Classes (8
th
to 12
th
) By: Er Hershit Goyal (B.Tech. IIT BHU), 134-SF, Woodstock Floors, Nirvana Country, Sector 50, GURUGRAM +91 9599697178.
fb.me/thehgclasses linkedin.com/company/the-hg-classes instagram.com/the_hg_classes g.page/the-hg-classes-gurugram thehgclasses.co.in
Is matter around us pure?
Mixture:
• It contains more than 1 substance (pure substance) mixed in any proportion.
• It can be separated into its constituents using appropriate separation techniques.
• Mixtures are of 3 types:
o Solution - A solution is a homogeneous mixture of two or more substances. The major
component of a solution is called the solvent, and the minor, the solute.
o Suspension – A heterogeneous mixture of an insoluble material in a solvent and have
particles visible to naked eye.
o Colloids – They are heterogeneous mixtures in which the particle size is too small to be seen
with the naked eye, but is big enough to scatter light. Colloids are useful in industry and
daily life. The particles are called the dispersed phase and the medium in which they are
distributed is called the dispersion medium.
Comparison Table of Mixtures:
Homogeneous
• They have uniform composition
throughout
Heterogeneous
▪ don’t have uniform composition throughout
SOLUTION
SUSPENSION
COLLOIDS
• one substance (solute) dissolves in
another (solvent).
• Particles intermix with each other.
• Particles of one substance
are distributed in the
other.
• Particles settle after some
time.
• Particles of one substance
are distributed in the other.
• Particles don’t settle with
time, remain suspended.
Particle
size
• small to be seen with
naked eye (< 1 nm)
• big enough to be visible to
naked eye
• intermediate, but big
enough to scatter light.
Example
• salt and water
• sugar and water
• water in alcohol
• sand and water
• milk
• blood
Scattering
of light
• No
• Yes or can be opaque
• Yes
Separation
• Evaporation
• Filtration
• Centrifugation
Concentration of a Solution: It is the amount of solute (mass or volume) present in per unit volume or per
unit mass of the solution.
Ways of expressing conc. of a solution:
Mass by Volume
Volume by Volume
Mass of solutⅇ
Volumⅇ of solution
∗ 100
Volumⅇ of solutⅇ
Volumⅇ of solution
∗ 100
Saturated Solution: At any particular temperature, a solution that has dissolved as much solute as it is
capable of dissolving, is said to be a saturated solution, otherwise it is unsaturated.
Hg
Name: Class 9
___________________________________________________________________________________________________________________________________
___________________________________________________________________________________________________________________________________
The Hg Classes (8
th
to 12
th
) By: Er Hershit Goyal (B.Tech. IIT BHU), 134-SF, Woodstock Floors, Nirvana Country, Sector 50, GURUGRAM +91 9599697178.
fb.me/thehgclasses linkedin.com/company/the-hg-classes instagram.com/the_hg_classes g.page/the-hg-classes-gurugram thehgclasses.co.in
Various techniques to separate mixtures:
• Evaporation, Sublimation
• Decantation, Filtration
• Chromatography
• Distillation and Fractional Distillation
• Centrifugation
• Using separating funnel for two immiscible liquids
Pure Substances:
• Elements – It is form of matter that CANNOT be broken down into simpler substances by chemical
means. e.g., oxygen, carbon, hydrogen.
o Metals – lustrous, heat conductors, electricity conductors, ductile, malleable, sonorous,
silvery grey or golden yellow, solid form at room temp (mercury is liquid)
▪ Example – Sodium, Copper, Iron, Potassium, Zinc, Aluminium, Mercury
o Non Metals – non-lustrous, non-sonorous, non-malleable, non-conductors of heat &
electricity, display variety of colours, mostly gas or liquid.
▪ Example – Hydrogen, Oxygen, Chlorine, Iodine, Carbon etc.
o Metalloids – show properties of both metals and non-metals
▪ Example – Boron, Silicon, Germanium
• Compounds – It is a substance composed of two or more different type of elements, chemically
combined in FIXED proportion. e.g., Water (H
2
O), carbon dioxide (CO
2
), methane (CH
4
).
Difference between compounds and mixtures:
Compounds
Mixtures
• Have fixed composition of its constituents
• Have variable composition of its constituents
• Their properties are different from its
constituents’ elements
• They show the properties of their constituents
• The constituents can be separated only by
chemical and electrochemical reactions
• Their constituents can be separated by easy
physical methods