Most Expected Chemistry Question Collections for exams

1. Age of fossils archeological excavation is determined by radio active carbon (C14).
2. Diamond has maximum refractive index and due to total internal reflection. It has lusture.
3. Chloroform in sunlight forms poisonous gas ‘Phosgene’ (COCl2).
4. To decease the basicity of soil gypsum is used.
5. In the preparation of Talcon powder deo phestal mineral is used.
6. Potassium chloride is the most suitable for removal of permanent hardness of water.
7. To avoid melting of ice gelatin is used.
8. When dry ice is heated it is directly converted into gas.
9. Saccharine is prepared from toluene.
10. Cream is type of milk in which amount of fat increased while amount of water decrease.
11. From one kilogram of honeybee 3500 calorie energy is produces.
12. N2O  is known as the laughing gas.
13. Bones contain about 58% calcium phosphate.
14. Phosphine gas is used I voyage as Holmes signal.
15. Chlorine gas bleaches the colour of flower.
16. Red phosphorus is used in match industry.
17. Urea contain 46% nitrogen.
18. In the electroplating of vessel NH4Cl is used.
19. Power alcohol is prepared from mixing pure alcohol iin benzene which  is used as rocket fuel.
20. Artificial perfumes are prepared from Ethyl acetate.
21. Urea was the first organic compound synthesized in laboratory.
22. Vinegar contain 10% acetic acid.
23. Acetylene is used for light production.
24. Ferric chloride is used to stop bleeding.
25. Barium is responsible for green colour in fireworks.
26. Cesium is used in solar cells.
27. Yellow phosphorus is kept in water.
28. Sea weeds contain iodine.
29. During cooking maximum vitamin is lost.
30. For the preparation of silver mirror , glucose is used.
31. When cream is separated from milk , it’s density increases.
32. For artificial respiration mixture of oxygen and helium gas cylinder is used.
33. In cold places to decrease the freezing point ethylene glycol is used.
34.  Hydrogen peroxide is used for oil paintings.
35.  Sodium is kept in kerosene oil.
36. The heaviest element is Osmium (Os).
37. The lightest element , least dense and most reductant is lithium (Li).
38. Flourine is most oxidising agent.
39. Silver is the best conductor of electricity.
40. Radon is the heaviest gas.
41. Polonium has the maximum number of isotopes.
42. Sulphuric acid is known as oil vitriol.
43. Noble Metals— Ag, Au, Pt, Ir, Hg, Pb, Rh, Ru and Os.

Some common man made polymers and their uses

Polymer	Use
Polythene	Packing materil, carry bags, bottles.
Polypropene	Bottles, Crates
Polyvinyl chloride (PVC)	Pipes insulation
Nylon (Polyester)	Fibres, ropes
Teflon	Nonstick kitchen ware
rubber	Rubber erasers
Polystyrene	Foam thermocole
Poly (Styrene butadiene)	Rubber bubble gum
Bakelite	Electrical insulation buttons
Lexan	Bullet proof glass
Melamine	Crockery

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