Students can Download Science Chapter 16 States of Matter Questions and Answers, Notes Pdf, KSEEB Solutions for Class 8 Science helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.
Karnataka State Syllabus Class 8 Science Chapter 16 States of Matter
KSEEB Class 8 Science States of Matter Textbook Exercise Questions and Answers
I. Four Alternatives are given to each of the following questions.
Question 1.
Which of the following does not hold good for liquids?
(a) They have a definite volume
(b) They are slightly compressible than solids
(c) Molecules free to move within the substance
(d) They have definite shape and size
Answer:
(d) They have definite shape and size
Question 2.
Which of the following is not a pure substance?
(a) Common salt
(b) Sugar
(c) Rain water
(d) Iron
Answer:
(c) Rain water
Question 3.
The component which is not present in air is
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Chlorine
Answer:
(d) Chlorine
Question 4.
Butter is an example of
(a) Liquid in solid
(b) Solid in liquid
(c) Liquid in liquid
(d) Solid in solid.
Answers:
(b) Solid in Liquid.
II. Answer the following questions
Question 1.
Write any four differences between solid, liquids and gases.
Answer:
Solid:
- has a definite mass, volume and shape.
- hard and rigid
- molecules are densely packed with least intermolecular distance
- the cohesive force between the molecules is maximum.
Liquid:
- has fixed mass and volume but no fixed shape.
- takes the shape of a container.
- molecules are not densely packed as in solids and the inter molecular space is more than that of solids.
- the cohesive force is less than that of solids.
Gas:
- has definite mass but no definite shape or volume.
- the volume depends on the size of the container.
- the molecules can move independently in all directions and have the maximum intermolecular distance.
- has the least cohesive force between the molecules.
Question 2.
Differentiate b/w homogeneous and heterogeneous solutions with an example to each.
Answer:
| Homogeneous Solution | Heterogeneous Solution |
| Here the composition is uniform throughout Ex : Brine solution |
Here the different constituents do not mix uniformly Ex : Mixture of water and oil |
Question 3.
Give an example to each of the following
Answer:
(a) suspension – eg:- saw dost or chalk dust (solute) added to water (solvent)
(b) Colloidal solution: eg Milk
Question 4.
Define
Answer:
(a) Tyndall effect: The scattering of a beam of light by the colloids is called the Tyndall effect
(b) Brownian movement: The random motion (zing-zag motion) of small colloidal particles suspended in a liquid or gas medium is called a Brownian movement
Question 5.
Give any two examples for solvents other than water
Answer:
Turpentine oil, chloroform (CCll4), CS2 Acetone, petrol, etc are some other solvents
III. Give the scientific reason for the following:
Question 1.
Gases do not have definite shape and volume
Answer:
Because the molecules in a gas are very for apart compared with the molecules in a solid or a liquid
Question 2.
Ornamental gold is an example for homogeneous mixture
Answer:
Because gold is too soft for many uses it is mixed with other metals like copper’ to make it harder.
Question 3.
The mixture of and andiron filings is a heterogeneous mixture
Answer:
Because they do not mix uniformly and components of the mixture are visible to the naked eye.
Question 4.
Water is called the universal solvent
Answer:
Because water is capable of dissolving a variety of different substances in it
Question 5.
When a beam of light is passed through a suspension, its path is visible
Answer:
Because a suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium.
IV. Match the following
1. Sodium chloride – (a) Impure substance
2. Milk – (b) Suspension solution
3. Air – (c) Pure substance (1), (d) Mixture (3)
Answers.
1. c,
2. b,
3. d
KSEEB Class 8 Science States of Matter Additional Questions and Answers
Question 1.
What is the matter?
Answer:
Anything that occupies space and has mass, is called matter,
Question 2.
Mention the properties of matter.
Answer:
The two properties of matter are
(a) Matter has mass.
(b) It occupies space and has weight.
Question 3.
The molecules of the solids have the least kinetic energy. Why?
Answer:
The intermolecular distance is the least in the case of solids. There is not much space between the molecules. Hence, molecules do not have much freedom to move. They merely vibrate in their own position. Therefore molecules have the least kinetic energy.
Question 4.
What is L.P.G?
Answer:
L.P.G is the liquefied petroleum gas in which the main component is butane. This is used as a domestic fuel. It is stored in the cylinder in the form of liquid, once the pressure is released, it changes into the gaseous state.
Question 5.
Cooking oil floats on water Why?
Answer:
Cooking oil floats on the water since the density of oil is lesser than that of water.
Question 6.
Name the device used to measure the purity of milk. Mention density of milk.
Answer:
Lactometer is the device used to measure the purity of milk. The Unadulterated milk should give a reading of 1.026 g/cm3on the lactometer,
II. Fill in the blanks:
Question:
1. The symbol used for density is _______________.
2. The intermolecular distance is least in _______________ state.
3. The inter molecular distance is highest in _______________ state.
4. The purity of materials is based on their _______________.
5. The density of Mercury is _______________.
Answers:
1. P [rho],
2. solid,
3. gaseous,
4. density,
5. 13.6 g/cm3
III. Choose the best alternative from the following:
Question 1.
The state of matter in a star is
(a) liquid
(b) gaseous
(c) plasma
(d) liquid crystal
Answer:
(c) plasma
Question 2.
S.l unit of specific gravity
(a) g/cm3
(b) Kg/m3
(c) m/v
(d) no unit
Answer:
(d) no unit
Question 3.
The symbol used for density is
(a) λ
(b) α
(c) P
(d) a
Answer:
(c) P
Question 4.
The law of floatation was proposed by
(a) Archimedes
(b) Galileo
(c) Dalton
(d) Newton
Answer:
(a) Archimedes
Question 5.
The expression for specific gravity is
(a) P of sub + P of water
(b) P of water + P of sub
(c) P of sub x P of water
(d) P of sub + P of water
Answer:
(a) P of sub + P of water