21. The negative logarithmic value of hydrogen on is called

1. 1. pH

   
   
   

   2. pOH

   
   
   

   3. pK_a

   
   
   

   4. pK_b

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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22. Which is the weakest acid ?

1. 1. HCI

   
   
   

   2. HCN

   
   
   

   3. HNO₃

   
   
   

   4. HCIO₄

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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23. In pure water hydrogen ion concentration is

1. 1. 10^-7

   
   
   

   2. 10^-10

   
   
   

   3. 10^-2

   
   
   

   4. 10^-1

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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24. The pH of water at 25° C is 7 When it is heated to 100°C, the pH of water

1. 1. increases

   
   
   

   2. decreases

   
   
   

   3. remains same

   
   
   

   4. decreases up to 50°C and then increases

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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25. When Metal carbonate reacts with dilute acids, forms

1. 1. H₂S

   
   
   

   2. NO₂

   
   
   

   3. CO₂

   
   
   

   4. CO

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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