251. The structure of boric acid is

1. 1. Planer

   
   
   

   2. Tertrahedral

   
   
   

   3. Trigonal planer

   
   
   

   4. Hexagonal

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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252. Why are noble gases called so ?

1. 1. They react quickly with other compound

   
   
   

   2. Due to their chemical inertness

   
   
   

   3. They react only with carbon compound

   
   
   

   4. They can produce oxygen

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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253. Carborundum is formed by the reaction of

1. 1. Si + Mg

   
   
   

   2. SiO₂ + C

   
   
   

   3. Si + Ca

   
   
   

   4. Na₂CO₃ + Si

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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254. Blasting of T.N.T. is made by mixing

1. 1. NH₄NO₂

   
   
   

   2. NH₄CI

   
   
   

   3. (NH₄)₂SO₄

   
   
   

   4. NH₄NO₃

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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255. Which of the following can not be used as nitrogenoum fertilizer ?

1. 1. CaNCN

   
   
   

   2. NH₄NO₃

   
   
   

   3. HNO₃

   
   
   

   4. NH₂CONH₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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