Question

1. Which separation techniques will you apply for the separation of :
(i) Tea leaves from tea.
(ii) Sodium chloride from its solution in water.
(iii) Iron pins from sand.
(iv) Different pigments from an extract of flower petals.
2. What is the effect of change of temperature on the solubility of a salt?
(i) Kinetic energy of molecules decreases
(ii) Kinetic energy of molecules increases
(iii) Kinetic energy become constant
(iv) None of the above
3. Choose a homogenous mixture among the following :
(i) Sugar and sand solution
(ii) Ice cubes in cola
(iii) Sugar in water
(iii) Concrete
4. How would you confirm that a colourless liquid given to you is pure water?
(i) By checking its solubility
(ii) By checking its boiling point
(iii) By drinking it
(iv) All of the above
5. Which one of the following material fall in the category of a “pure substance”?
(i) Fruit Salad
(ii) Muddy water
(iii) Mercury
(iii) Milk
6. Identify the solutions among the following mixtures.
(i) Soil
(ii) Soda Water
(iii) Coal
(iv) Sea water
7. Which of the following will show “Tyndall effect”?
(i) Salt solution
(ii) Copper sulphate solution
(iii) Milk
(iv) None of the above
8. Which one of the following is a chemical change ?
(i) Burning of wood
(ii) Milk becoming curd
(iii) Digestion of food
(iv) All of the above
9. Which one of the following is a physical change ?
(i) Formation of caramel from sugar
(ii) Baking of cookies and cakes
(iii) Cooking any food
(iv) Crushing a can
10. Which one of the following cannot be broken into simpler substances ?
(i) Compounds
(ii) Mixtures
(iii) Elements
(iv) Colloids
11. What do we get when two or more elements are combined?
(i) Atoms
(ii) Molecules
(iii) Compounds
(iv) None of the above
12. How can we obtain pure copper sulphate solution from impure sample ?
(i) By Crystallization method
(ii) By Distillation Method
(iii) By Chromatography technique
(iv) By using separating funnel

Answer 1

Answer:

50+ 60 +50=130 so b= 90

Explanation:

Answer 2

Answer:

Q1)

I) sieving

ii) pata nhi.

iii)magnitisation

iv) pata nhi

Q2