TEST PAPER 25 : CHAPTER 11 : NONMETALS : 25 MARKS

There are 13 questions in all and time limit is 45 minutes.

SECTION - A : CHOOSE APPROPRIATE ALTERNATIVE : [1 mark each, Total marks 3]

1. The formula of carbonic acid is ______.
   
   
   
   1. H₂CO₃
   2. H₃CO₂
   3. HCO₃
   4. H₂CO₂
      
   
   
2. How many nonmetals are in gaseous state ?
   
   
   
   1. 7
   2. 8
   3. 9
   4. 10
      
   
   
3. The transition temperature of sulphur is ___ °C.
   
   
   
   1. 90
   2. 92
   3. 94
   4. 96
      
   
   

   SECTION - B : ANSWER IN SHORT : [1 mark each, Total marks 3]
   

4. Give the example of a nonmetal which conducts heat & electricity.
5. Why is ammonia not collected by downward displacement of water ?
6. Which crystalline form of sulphur is the most stable ?
   
   

   SECTION - C : ANSWER IN BRIEF : [2 marks each, Total marks 8]
   

7. Write chemical equations : (i) When phosphorus pentoxide is dissolved in water.(ii) When ammonia reacts with oxygen in presence of platinum.
8. Mention four uses of ammonia.
9. Mention four physical properties of sulphur.
10. Describe preparation of sulphur from natural gas and oils.
    
    

    SECTION - D : ANSWER THE FOLLOWING : [3 marks each, Total marks 6]
    

11. Describe allotropes of sulphur(diagrams not necessary).
12. Describe manufacture of sulphuric acid by contact process.
    
    

    SECTION - E : ANSWER IN DETAIL : [5 marks each, Total marks 5]
    

13. Describe laboratory preparation of hydrogen with diagram.