151. Philosopher’s Wool is
     

1. 1. Zinc carbonate
      

   
   
   

   2. Zinc sulphate
      

   
   
   

   3. Zinc oxide
      

   
   
   

   4. Zinc blende

   
   
   

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1. View Hint View Answer Discuss in Forum

   Philosopher’s wool is chemically zinc oxide.

   Correct Option: C

   Philosopher’s wool is chemically zinc oxide.

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152. ‘Aerosol’ is
     

1. 1. Suspended solid particles in air
      

   
   
   

   2. Pollutant gas, present in air
      

   
   
   

   3. Microbes, present in air
      

   
   
   

   4. Green house gas present in air

   
   
   

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1. View Hint View Answer Discuss in Forum

   Aerosol is suspended solid particles in the air.

   Correct Option: A

   Aerosol is suspended solid particles in the air.

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153. The main source of carbon monoxide is
     

1. 1. Industrial process
      

   
   
   

   2. Fuel combustion

   
   
   

   3. Transportation

   
   
   

   4. Solid waste disposal

   
   
   

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1. View Hint View Answer Discuss in Forum

   The main source of carbon monoxide is burning of fossil fuel.

   Correct Option: C

   The main source of carbon monoxide is burning of fossil fuel.

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154. In its reaction with silver nitrate, C2H2 shows
     

1. 1. Oxidising property
      

   
   
   

   2. Reducing property
      

   
   
   

   3. Basic property
      

   
   
   

   4. Acidic property

   
   
   

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1. View Hint View Answer Discuss in Forum

   When treated with ammoniacal silver nitrate solution alkynes form white precipitate of silver acetylides.

   Correct Option: D

   When treated with ammoniacal silver nitrate solution alkynes form white precipitate of silver acetylides.

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155. Earth’s atmosphere is an envelope of gases extending to a height of
     

1. 1. 100 km
      

   
   
   

   2. 150 km
      

   
   
   

   3. 200 km
      

   
   
   

   4. 300 km

   
   
   

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1. View Hint View Answer Discuss in Forum

   The atmosphere of the Earth is an envelope of gases extending to a height of 200km.

   Correct Option: C

   The atmosphere of the Earth is an envelope of gases extending to a height of 200km.

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