36. Which of the following processes is used to remove reducible oxides from the metal ?

1. 1. Liquation

   
   
   

   2. Cupellation

   
   
   

   3. Poling

   
   
   

   4. Electro refining

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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37. The formula of azurite is

1. 1. CuCO₃ .2Cu(OH)₂

   
   
   

   2. 2CuCO₃ .Cu(OH)₂

   
   
   

   3. CuCO_3. .Cu(OH)₂

   
   
   

   4. CuSO₄ .Cu(OH)₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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38. Calcium decomposes water and liberates

1. 1. H₂

   
   
   

   2. O₂

   
   
   

   3. CaO

   
   
   

   4. CaO₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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39. Which of the following is formed when beryllium burns in oxygen ?

1. 1. Be₂O

   
   
   

   2. BeO

   
   
   

   3. BeO₂

   
   
   

   4. Be₂O₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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40. The purification of alumina is done by

1. 1. Baeyer's process

   
   
   

   2. Hoop's process

   
   
   

   3. Bosch process

   
   
   

   4. Castner process

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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