81) In colorful diamond, different colors are present due to:
(A) Impurities
(B) Angular bonds between the carbon atoms
(C) Different patterns of carbon chains
(D) None of the above
82) All of the followings are different uses of hydrogen peroxide except
(A) Used as bleaching agent
(B) Used to de-odor sewers
(C) Used as fuel in space
(D) Used to prepare organic peroxides
83) Ozone is present in which of the following layers of atmosphere
(A) Troposphere and Thermosphere
(B) Troposphere and Stratosphere
(C) Mesosphere
(D) Thermosphere
84) Which of the following method is used in manufacturing of sulphuric acid
(A) Contact process
(B) Frasch method
(C) Ostwald's method
(D) Haber's process
85) The process of smelting and cooling converts pig iron into
(A) Silicon steel
(B) Cast iron
(C) Wrought iron
(D) Steel
86) Pure iron is obtained by the reduction of which of the followings in the blast furnace
(A) Haematite
(B) Magnetite
(C) Iron oxide
(D) Limonite
87) Methane is used in daily life with the name of
(A) Carbon Dioxide
(B) Natural Gas
(C) Carbon Monoxide
(D) Calcium Carbonate
88) When electricity is passed through neon it glows.
(A) Blue
(B) Green
(C) Red
(D) Yellow
89) Argon and which gas is used in various types of fluorescent and phototubes
(A) Oxygen
(B) Helium
(C) Neon
(D) Krypton
90) Enzymes are
(A) Chemical catalyst
(B) Biological catalyst
(C) Organic catalyst
(D) Inorganic catalyst