CBSE ADDA
1. The type of glass used in making lenses and prisms is?
1. The type of glass used in making lenses and prisms is?
(a) soft glass
(b) pyrex glass
(c)jena glass
(d) flint glass
(b) pyrex glass
(c)jena glass
(d) flint glass
2. Wood is the main raw material for the manufacture of ?
(a) paint
(b) paper
(c) ink
(d) gun powder
(a) paint
(b) paper
(c) ink
(d) gun powder
3. How does common salt help in separating soap from the solution after saponification?
(a) By decreasing solubility of soap
(b) By increasing solubility of soap
(c) By decreasing density of soap
(d) By increasing density of soap
(a) By decreasing solubility of soap
(b) By increasing solubility of soap
(c) By decreasing density of soap
(d) By increasing density of soap
4. Which of the following is commonly called a ‘polyamide’?
(a) Rayon
(b) orlon
(c)Terylene
(d) Nylon
(a) Rayon
(b) orlon
(c)Terylene
(d) Nylon
5. The major ingredient of leather is ?
(a)carbohydrate
(b) collagen
(c)polymer
(d) nucleic acid
(a)carbohydrate
(b) collagen
(c)polymer
(d) nucleic acid
6. In the manufacture of safety matches, which of the following materials are used to coat the two sides of match boxes?
1. Yellow phosphorus
2. Glue
3, Glass powder
4. Red phosphorus
(a) l, 2 and 3
(b) l,3 and 4
(c) l,2 and 4
(d) 2,3and4
1. Yellow phosphorus
2. Glue
3, Glass powder
4. Red phosphorus
(a) l, 2 and 3
(b) l,3 and 4
(c) l,2 and 4
(d) 2,3and4
7. Glass is made of the mixture of ?
(a)quartz and mica
(b) sand and salt
(c)sand and silicates
(d) None of these
(a)quartz and mica
(b) sand and salt
(c)sand and silicates
(d) None of these
8. Epoxy resins are used as
(a)moth repellants
(b) insecticides
(c)detergents
(d) adhesives
(a)moth repellants
(b) insecticides
(c)detergents
(d) adhesives
9.What is condensation?
(a) Change of gas into solid
(b) Change of solid into liquid
(c) Change of vapour into liquid
(d) Change of heat energy into cooling energy
(a) Change of gas into solid
(b) Change of solid into liquid
(c) Change of vapour into liquid
(d) Change of heat energy into cooling energy
10. Which of the following are true regarding a
catalyst?
1. It is a substance which increases the rate of reaction.
2. It is a substance which reduces the activation energy.
3. It is a substance which increases the activation energy.
4. It is a substance which is consumed in the reaction.
(a) l and 2
(b) 2 and 3
(c) 3 and 4
(d) l and 4
catalyst?
1. It is a substance which increases the rate of reaction.
2. It is a substance which reduces the activation energy.
3. It is a substance which increases the activation energy.
4. It is a substance which is consumed in the reaction.
(a) l and 2
(b) 2 and 3
(c) 3 and 4
(d) l and 4
11. Which of the following is a physical change?
(a)Oxidation
(b) Reduction
(c)Sublimation
(d) Decomposition
(a)Oxidation
(b) Reduction
(c)Sublimation
(d) Decomposition
12. A substance which changes readily into vapour without heating is called ?
(a)efflorescent
(b) synthetic
(c) volatile
(d) effervescent
(a)efflorescent
(b) synthetic
(c) volatile
(d) effervescent
13. Catalytic properties of a substance may be best defined as a phenomenon of ?
(a) Absorption
(b) Chemisorption
(c) Adsorption
(d) None of these
(a) Absorption
(b) Chemisorption
(c) Adsorption
(d) None of these
14. In which of the following processes light energy is converted into chemical energy?
(a)Respiration
(b) Fermentation
(c)Photosynthesis
(d)Photorespiration
(b) Fermentation
(c)Photosynthesis
(d)Photorespiration
15. Photosynthesis is?
(a) an exothermic process
(b) an endothermic process
(c) a neutral process
(d) a thermostatic process
(a) an exothermic process
(b) an endothermic process
(c) a neutral process
(d) a thermostatic process
16. Combustion is the process in which ?
(a) heat is produced.
(b) light is produced.
(c) heat and light are produced.
(d) None of these
(a) heat is produced.
(b) light is produced.
(c) heat and light are produced.
(d) None of these
17. The chemical used as a ‘fixer’ in photography is
(a) borax
(b) sodium thiosulphate
(c) sodium sulphate
(d) ammonium persulphate
(a) borax
(b) sodium thiosulphate
(c) sodium sulphate
(d) ammonium persulphate
18. The rate of chemical reaction does not depend upon ?
(a) Concentration
(b) Catalyst
(c)Temperature
(d) Pressure
(a) Concentration
(b) Catalyst
(c)Temperature
(d) Pressure
19. Which of the following is a chemical change?
(a) Magnetisation of iron
(b)Melting of ice
(c) Burning of sulphur
(d)Melting of wax
(a) Magnetisation of iron
(b)Melting of ice
(c) Burning of sulphur
(d)Melting of wax
20. Which of the following substances undergoes chemical change on heating?
(a) Sodium chloride
(b) Silica
(c) Lead nitrate
(d) Platinum wire
(a) Sodium chloride
(b) Silica
(c) Lead nitrate
(d) Platinum wire
21. Water is neither acidic nor alkaline because
(a) it cannot accept or donate protons.
(b) it boils at a high temperature.
(c) it can dissociate into equal number of hydrogen ions.
(d) it cannot donate or accept electrons.
(a) it cannot accept or donate protons.
(b) it boils at a high temperature.
(c) it can dissociate into equal number of hydrogen ions.
(d) it cannot donate or accept electrons.
22. Chemical change does not take place in case of?
(a) souring of milk into curd
(b) rusting of iron in atmosphere
(c) burning of magnesium ribbon in air
(d) emitting of light by a red hot platinum wire
(a) souring of milk into curd
(b) rusting of iron in atmosphere
(c) burning of magnesium ribbon in air
(d) emitting of light by a red hot platinum wire
23. Vulcanization is a ?
(a) science of studying volcanoes
(b) method to degrade polymers
(c) process connected with the making of voltaic cells
(d) process of hardening of robber by heating it with sulphur
(a) science of studying volcanoes
(b) method to degrade polymers
(c) process connected with the making of voltaic cells
(d) process of hardening of robber by heating it with sulphur
24. Which of the following causes the rusting of iron?
1. Oxidation
2. Reduction
3. Chemical reaction with oxygen
4. Chemical reaction with CO
(a) l and 2
(b) 2 and 3
(c) 3 and 4
(d) l and 3
1. Oxidation
2. Reduction
3. Chemical reaction with oxygen
4. Chemical reaction with CO
(a) l and 2
(b) 2 and 3
(c) 3 and 4
(d) l and 3
25. Which of the following statements is/are true?
1. The process of oxidation leads to a gain of electrons.
2. The process of oxidation leads to a Toss of electrons.
3. The process of reduction leads to a gain of electrons.
4. The process of reduction leads to a loss of electrons.
(a) l only
(b) l and 4
(c) 2 and 3
(d) 4 only
1. The process of oxidation leads to a gain of electrons.
2. The process of oxidation leads to a Toss of electrons.
3. The process of reduction leads to a gain of electrons.
4. The process of reduction leads to a loss of electrons.
(a) l only
(b) l and 4
(c) 2 and 3
(d) 4 only
26. Light year is a unit of measurement of
(a) speed of light
(b) stellar distances
(c) speed of rockets
(d) speed of aero planes
(b) stellar distances
(c) speed of rockets
(d) speed of aero planes