The comprehensive approach in SCERT Class 6 Basic Science Textbook Solutions Chapter 5 Association of Substances Important Questions ensure conceptual clarity.
Association of Substances Extra Questions and Answers Class 6 Basic Science Chapter 5 Kerala Syllabus
Association of Substances Class 6 Important Questions
Question 1.
a) It is prescribed to “Shake well before use” outside the bottles of medicine given to small children having fever. Give reason.
b) Glucose solution and bottles of medicine given to patients are mixtures. How do they differ from each other?
Answer:
a) Substances present in bottle are heterogeneous mixtures. They settle down at the bottom. We shake the bottle well to get same properties throughout all its parts.
b) Glucose solution is a homogeneous mixture. The particles present in glucose solution are not visible. Bottle of medicine is a heterogeneous mixture in which particles are visible clearly.
Question 2.
a) What is a molecule?
b) Arrangement of molecules in solids, liquids and gases are shown below. Identify the states A, B and C.
c) Substances in w hich state of matter has a definite shape. Why?
d) Gases can spread fast. Why?
Answer:
a) Molecule is the smallest particle of a substance having all its properties. All substances are made up of molecules.
b) A : liquid state, B : gaseous state, C : solid state
c) In solids, molecules are closely packed and the attraction between molecules are very strong. So solids have a definite shape.
d) Gases have a lot of space between the molecules and does not have strong force of attraction between them. They can move freely in all directions quickly. Hence gases can spread fast.
Question 3.
Identify whether the statements given below are true or false. Also correct the false statements.
a) Buttermilk is a homogeneous mixture.
b) Gold jewels are a kind of solution.
c) All mixtures are solutions.
d) Sand mixed with iron dust can be separated by blowing air.
Answer:
a) False. Buttermilk is a heterogeneous mixture.
b) True.
c) False. All mixtures are not solutions. Solutions are homogeneous mixtures.
d) False. Sand mixed with iron dust can be separated by using a magnet.
Question 4.
Some solutions are given below. Categorise them appropriately.
(Vinegar, copper sulphate solution, ammonia solution, soda water, soap solution, dilute acid, tap water, sanitizer, salt solution)
Answer:
| Solid-liquid solution | Liquid-liquid solution | Gas-liquid solution |
| • Salt solution • Copper sulphate solution • Soap solution |
• Vinegar • Dilute acid • Sanitizer |
• Soda water • Ammonia solution • Tap water |
Question 5.
Analyse the different substances given below. Choose the appropriate ones and complete the concept map.
| Homogeneous mixtures, Water, Sugar solution. Concrete, Mixtures, Fruit salad. Soda water. Oxygen |
Answer:
a) Water
b) Oxygen
c) Mixtures
d) Homogeneous mixtures
e) Sugar solution
f) Soda water
g) Concrete
h) Fruit salad
Question 6.
Analyse the components of air shown below and answer the questions given below.
| Gas | Quantity |
| Nitrogen | 78% |
| Carbon dioxide | 0.04% |
| Oxygen | 21% |
| Others | 0.96% |
a) Which component of air is seen in large quantity?
b) Which component of air is used up by plants during photosynthesis?
c) Air is said to be a mixture. Why?
d) Point out a situation that adversely effects the equilibrium of components of air?
Answer:
a) Nitrogen (78%)
b) Carbon dioxide
c) Air has more than one substance such as nitrogen, oxygen, carbon dioxide etc and is said to be a mixture.
d) Burning plastics’causes mixing of toxic substances with air.
Question 7.
a) What is meant by homogeneous mixture and heterogeneous mixture?
b) Categorize the following mixtures into homogeneous mixtures and heterogeneous mixtures.
| Salt solution, Gold jewels, Pickle powder. Ayurvedic medicines, Vinegar, Washing powder |
Answer:
a) The mixture that shows the same properties throughout all its parts is called a homogeneous mixture. The mixture that shows different properties in different parts is called a heterogeneous mixture.
b) Homogeneous mixtures: Salt solution, Gold jewels, Vinegar.
Heterogeneous mixtures: Pickle powder, Ayurvedic medicines, Washing powder.
Question 8.
Analyse the table given below and complete the table appropriately
| Substance | Components involved | Pure substance/Mixture |
| Copper sulphate solution | a) | b) |
| Hot water | c) | d) |
| Aluminium | e) | f) |
| Soda water | g) | h) |
Answer:
a) Copper sulphate, water
b) Mixture
c) Water
d) Pure substance
e) Aluminium
f) Pure substance
g) Carbon dioxide, water
h) Mixture
Question 9.
Note the illustration showing the molecules in different substances and answer the following questions.
a) Which of the above represents pure substances?
b) Which of the above represents mixtures?
c) What is the basis of your findings?
Answer:
a) Pure substances are P and S
b) Mixtures are Q and R
c) Pure substances are substances made up of same type of molecules.
Mixtures have different types of molecules in them.
Question 10.
Complete the table related to the methods of separation of mixtures.
| Situations | Method of separation | Associated property of components |
| Separating salt from seawater | a) | Water changes to vapour |
| Separating tea leaves from tea | b) | c) |
| Separating chaff from paddy | d) | Difference in weight of the components |
| Separating Iron powder from sand. | e) | f) |
Answer:
a) Evaporation
b) Filtration
c) Difference in size of the components
d) Winnowing
e) Separation using magnet
f) Attraction of iron by a magnet