Q.2. Give three examples of mixtures
found in everyday life.
Q.3. What are the two main types of
mixtures?
Q.4. Define a homogeneous mixture and
give two examples.
Q.5. Define a heterogeneous mixture and
give two examples.
Answers:
A.1: A mixture is a combination of
two or more substances where each substance retains its
own chemical identity and properties. Mixtures can be
separated into their individual components by physical
means.
A.2: Examples of mixtures in everyday
life include air (a mixture of gases), ocean water (a
mixture of water and salts), and soil (a mixture of
organic matter, minerals, and organisms).
A.3: The two main types of mixtures are
homogeneous mixtures and heterogeneous mixtures.
A.4: A homogeneous mixture is a mixture
with a uniform composition throughout. Examples include
salt water and air.
A.5: A heterogeneous mixture is a mixture
that has a non-uniform composition. Examples include a
mixture of sand and water.
Q.2. Provide an example of obtaining
useful components from a mixture.
Q.3. Explain how separating harmful
substances from useful ones can benefit health and safety.
Q.4. Describe a scenario where
purification of substances is essential in an industry.
Answers:
A.1: It is important to separate mixtures
to obtain useful components, remove harmful substances,
and purify substances.
A.2: An example of obtaining useful
components from a mixture is the separation of crude oil
into petrol, diesel, and other products through fractional
distillation.
A.3: Separating harmful substances from
useful ones, such as purifying drinking water, is crucial
for health and safety as it removes contaminants that can
cause illness.
A.4: In the mining industry, separation
techniques are used to purify raw materials by removing
impurities from metals.
Q.3. List the equipment and
materials used in filtration.
Q.4. Describe the steps involved in the
filtration process.
Q.5. What is evaporation?
Q.6. Describe an experiment to
demonstrate evaporation.
Q.7. What is distillation?
Q.8. What is the difference between
simple distillation and fractional distillation?
Q.9. Describe the setup and steps
involved in simple distillation.
Q.10. What is magnetic separation?
Q.11. List the materials required
for magnetic separation.
Q.12. Describe the process of
magnetic separation.
Q.13. What is decantation?
Q.14. What equipment is used in
decantation?
Q.15. Describe the process of
solid-liquid decantation.
Q.16. Explain the steps in
liquid-liquid decantation.
Q.17. What is centrifugation?
Q.18. Describe the process of
centrifugation.
Q.19. What is sieving?
Q.20. What equipment is used in
sieving?
Q.21. Describe the steps in the
sieving process.
Answers:
A.1: Filtration is the process of
separating insoluble solids from a liquid using a filter.
A.2: Filtration works by passing a
mixture through a filter medium, which allows the liquid
to pass through while retaining the solid particles.
A.3: Equipment and materials used in
filtration include filter paper, funnel, beaker or flask,
and stirring rod.
A.4: Steps in the filtration process
include preparation (folding filter paper and placing it
in the funnel), pouring the mixture into the funnel,
allowing the liquid to pass through while the solid
remains, and removing the filter paper with the solid
residue.
A.5: Evaporation involves heating a
liquid to form vapor, leaving the dissolved solid behind.
A.6: An experiment to demonstrate
evaporation involves pouring equal amounts of water into
two shallow dishes, placing one dish in direct sunlight or
under a lamp and the other in the shade, and observing the
amount of water over time. The dish in
A.7: Distillation separates mixtures
based on differences in boiling points.
A.8: Simple distillation separates a
solvent from a solution, while fractional distillation
separates a mixture of liquids.
A.9: The setup includes a
distillation flask, condenser, receiving flask, heat
source, and thermometer. Steps include heating the liquid
mixture to its boiling point, vapor formation,
condensation of vapor back into a liquid, and collection
of the distilled liquid.
A.10: Magnetic separation uses magnets to
separate magnetic materials from non-magnetic ones.
A.11: Materials required include a
magnet, a mixture containing both magnetic and
non-magnetic substances, a container, and protective
equipment.
A.12: The process includes preparing the
mixture, bringing the magnet close to the mixture,
collecting the magnetic particles, and repeating until all
magnetic particles are separated.
A.13: Decantation involves carefully
pouring off a liquid to leave a solid or another liquid
behind.
A.14: Equipment used includes a beaker,
decantation flask or separating funnel, and a stirring
rod.
A.15: The process involves allowing the
mixture to stand undisturbed, pouring the liquid into
another container, and using a stirring rod to guide the
liquid.
A.16: Steps include pouring the
mixture into a separating funnel, letting it stand until
layers form, releasing the denser liquid from the bottom,
and closing the stopcock to leave the less dense liquid.
A.17: Centrifugation uses a centrifuge to
separate components based on their densities by spinning
them at high speed.
A.18: The process involves placing the
mixture into centrifuge tubes, ensuring balance, inserting
tubes into the centrifuge, setting the speed and time,
starting the machine, and separating components based on
density.
A.19: Sieving separates particles of
different sizes using a sieve.
A.20: Equipment includes a sieve,
sieving tray, and a brush or cleaning tool.
A.21: Steps include ensuring the sieve
and tray are clean, selecting the appropriate sieve,
placing the sieve over the tray, pouring the mixture onto
the sieve, shaking or tapping the sieve, and collecting
the separated particles.
Q.1. Why are separation techniques
important for safety and health?
Q.2. How do separation techniques
enhance the quality of products?
Q.3. Explain the role of separation
techniques in environmental protection and waste
management.
Answers:
A.1: Separation techniques are important
for safety and health because they remove harmful
substances from food and water to prevent illness.
A.2: Separation techniques enhance
the quality of products by purifying raw materials, which
improves the quality of the final products in industries
like pharmaceuticals and food processing.
A.3: Separation techniques play a role in
environmental protection and waste management by
separating recyclable materials from waste, reducing
pollution, and conserving resources
