Quiznetik

Chemistry | Set 13

1. What happens when a chemical bond is formed?

Correct : D. energy is neither released nor absorbed

2. Silver nitrate solution is kept in brown bottles in laboratory because -

Correct : B. brown bottles stops the passage of light through it

3. In upper layer of atmosphere ozone is formed by -

Correct : A. the action of ultraviolet rays on oxygen

4. Water is not effective in extinguishing a fire caused by petrol because –

Correct : D. water and petrol are immiscible with each other and petrol which forms the upper layer continues to burn

5. "All the four quantum numbers of two electrons in an atom are not the same." It is the law of

Correct : B. Exclusion Principle of Pauli

6. The three elements most needed in common fertilizers are –

Correct : B. Nitrogen, Phosphorous and Sodium

7. Metal are good conductors, because –

Correct : A. they contain free electrons

8. Helium gas is filled in ballons because

Correct : B. it is lighter than air

9. Ammonial is a mixture of –

Correct : A. aluminium powder and ammonium nitrate

10. Gelatin is mostly used in making icecreams in order to -

Correct : B. stabilise the colloid and prevent crystallisation

11. Glycol is added to aviation gasoline because it -

Correct : C. prevents freezing of petrol

12. Rust is -

Correct : D. A mixture of Fe₂O₃, 3H₂O and FeO

13. Catalyst is a substance which –

Correct : D. None of these

14. Table salt gets moist during rainy season because –

Correct : D. sodium chloride contains hygroscopic impurities like magnesium chloride

15. Which of the following could be used as fuel in propellant or rockets?

Correct : D. Liquid Hydrogen + Liquid Oxygen

16. The BOD values of water indicate the

Correct : B. amount of oxygen used for biochemical oxidation

17. The addition of gypsum to port-land cement helps in :

Correct : C. preventing rapid setting of cement

18. Milk is a colloidal system in which:

Correct : B. Fat is dispersed in water

19. The presence of ozone in the stratosphere is responsible for –

Correct : C. checking the penetration of ultra-violet rays to the earth

20. The advantage of detergents over soaps is –

Correct : C. Detergents give lather even with hard water

21. Cement is usually a mixture of –

Correct : A. Calcium silicate and calcium alurninate

22. What is the objective of the 'Kyoto Protocol'?

Correct : D. To reduce greenhouse gases

23. The lustre of the metals is because of –

Correct : C. reflection of light due to the presence of free electrons

24. Cloud is a colloidal dispersion of –

Correct : D. Water drops in a dispersion medium of air

25. Conduction band electrons have more mobility than holes because they –

Correct : B. experience collision less frequently

26. Carbon dioxide is called a greenhouse gas because -

Correct : C. it absorbs infrared radiation

27. Sullage water is –

Correct : A. waste water released from kitchen

28. A solution is -

Correct : A. a homogeneous mixture of two or more substances

29. Choose the incorrect statement pertaining to organic compounds -

Correct : C. They are not easily combustible

30. Which of the process is known as nitrification?

Correct : C. Conversion of ammonia to nitrites

31. Acid rain is caused due to pollution of atmosphere by –

Correct : B. oxides of nitrogen and sulphur

32. Neuron is -

Correct : D. Fundamental unit of nervous system

33. Water cycle refers to –

Correct : B. constant movement of water from ocean to land and back to ocean once again

34. When a spoon is to be electroplated with nickel the spoon is -

Correct : C. made cathode and a pure nickel red, the anode

35. Which of the following is not a method of preparing oxygen?

Correct : D. Decomposition of manganese dioxide

36. Which one of the following takes place during a nuclear fusion?

Correct : C. two light nuclei combine to form a heavy nucleus

37. Helium is added to the oxygen supply of deep sea divers because it is -

Correct : D. less soluble in blood than nitrogen at high pressure

38. The chemical bahaviour of an atom depends upon -

Correct : C. the number of electrons orbiting around the nucleus

39. Methyl phenyl ether can be obtained by reacting -

Correct : A. phenolate ions and methyl iodide

40. Acid Rain is caused due to pollution of atmosphere by –

Correct : C. Oxides of nitrogen and sulphur