21.The phenomenon, which doesn’t lead, to global, warming?
(A) Greenhouse effect
(B) CFCs
(C) Ozone depletion
(D) Photosynthesis
answer
(D) Photosynthesis
22. “Ultraviolet radiations” from sun ,that reach to, earth caused:
(A) Skin Cancer
(B) Respiratory Disorder
(C) Typhoid fever
(D) Bronchitis
answer
(A) Skin Cancer
23. The source of all, the following pollutants, in vehicle exhaust, except:
(A) CFCs
(B) Nitrogen Oxides
(C) Carbon Dioxide
D) None of these
answer
(A) CFCs
24. “Substance on the left hand side” of a chemical, equation is called:
(A) Electron
(B) Groups
(C)Product
(D) Reactants
answer
(D) Reactants
25. The reaction in, which there is only one ”reactants”, which must be compound, is:?
(A) Decomposition
(B) Synthesis
(C) Displacement
(D) Double Displacement
answer
(A) Decomposition
26. ”Number of atoms” of reactants, is equal to number ,of products in a: ______________ balanced chemical equation?
(A) Some time
(B) Never
(C) Often
(D) Always
answer
(D) Always
27. The reaction between ”Sodium and Chlorine” to from ‘Sodium Chloride’ is:
(A) Displacement
(B) Addition reaction
(C) Decomposition
(D) Double decomposition reaction
answer
(A) Displacement
28. The ”heat involved absorbed” during a chemical reaction is called:
(A) Heat of reaction
(B) Heat energy
(C) Exothermic
(D) Endothermic
answer
(A) Heat of reaction
29. Which one of the following ”acids” are used in car batteries called:
(A) HCL
(B) HNO3
(C) H2S04
(D) None of these
answer
(C) H2S04
30. The ”Alkali” used as an, antacid, is?
(A) Kott
(B) HNO3
C)H2S04
D) NACL
answer
D) NACL
