CBSE Board Class 11 Chemistry Previous Year Question Papers 2005

Previous Paper 
Class 11

1. Which orbital is non – directional?   

2. What is the meaning of quantization of energy? 

3. Why is energy of 1s electron lower than 2s electron?   

4. Which quantum number determines 
(i)  energy of electron              (ii) Orientation of orbitals. 

5. What is nodal surface or nodes?    

6. How many spherical nodal surfaces are there in 4s – sub-shell?   

7. Arrange the electrons represented by the following sets of quantem number
in decreasing order of energy.  
1.   n = 4,  l = 0, m = 0, s = +1/2 
2.   n = 3,  l = 1, m = 1,  s = -1/2
3.   n = 3,  l = 2, m = 0, s = +1/2 
4.   n = 3,  l = 0, m = 0, s = -1/2 

8. What designations are given to the orbitals having 
(i)    n = 2, l = 1     (ii)   n = 2, l = 0     (iii) n = 4, l = 3 
(iv)   n = 4, l = 2      (v)    n = 4, l = 1?  

9. Write the electronic configuration of (i) Mn4+
 (ii) Fe 3+
(iii)  Cr 2+ and Zn2+
Mention the number of unpaired electrons in each case. 

10. What is stoichiometry?         

11. How much potassium chlorate should be heated to produce 2.24L of 
oxygen at NTP?          

12. Write an expression for molarity and molality of a solution.    

13. Calculate the weight of lime (CaO) obtained by heating 2000kg of 95% pure 
lime stone (CaCO3)         

14. The substance which gets used up in any reaction is called --------------   

15. What is 1molal solution?         

16. 4 litres of water are added to 2L of 6 molar HCl solutions. 
What is the molarity of resulting solution?        

17. What volume of 10M HCl and 3M HCl should be mixed to obtain 1L of 
6M HCl solution?          

18. What is the general outer electronic configuration of f – block elements? 

19. Why do Na and K have similar properties?    

20. Arrange the following elements in the increasing order of metallic character :
Si, Be, Mg, Na, P.  

21. The atomic number of an element is 16. Determine its position in accordance
to its electronic configuration. 

22. Why are elements at the extreme left and extreme right the most reactive?  

23. Why does the ionization enthalpy gradually decreases in a group?  

24. Why does electronegativity value increases across a period and decreases
down period?  

25. How does electronegativity and non – metallic character related to each
other?