126. How many electrons are involved in the oxidation by KMnO₄ in basic medium ?

1. 1. 5

   
   
   

   2. 3

   
   
   

   3. 2

   
   
   

   4. 4

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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127. Iron loses magnetic property at

1. 1. Melting point

   
   
   

   2. Curie point

   
   
   

   3. 1000^°K

   
   
   

   4. Boiling point

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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128. When metal is obtained in the molten state from its ore, the process may be called

1. 1. Rusting

   
   
   

   2. Smelting

   
   
   

   3. Calcination

   
   
   

   4. Thermal dissociation

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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129. The solubility of AgBr in hypo is due to the formation of

1. 1. Ag₂S₂O₃

   
   
   

   2. [Ag(S₂O₃)]^-

   
   
   

   3. [Ag(S₂O₃)]^3-

   
   
   

   4. Ag₂SO₃

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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130. The formula of haematite is

1. 1. Fe₃O₄

   
   
   

   2. Fe₂O₃

   
   
   

   3. FeCO₃

   
   
   

   4. FeS₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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