#### Ionic Equilibrium Model Question Paper

12th Standard EM

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 40
5 x 1 = 5
1. Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.24 ×10-4mol L-1 solubility product of Ag2C2O4 is

(a)

2.42 ×10-8mol3L-3

(b)

2.66 ×10-12mol3L-3

(c)

4.5 ×10-11mol3L-3

(d)

5.619 ×10-12mol3L-3

2. Which of these is not likely to act as lewis base?

(a)

BF3

(b)

PF3

(c)

CO

(d)

F

3. What is the decreasing order of strength of bases
OH, NH2- H - C ≡ C and CH3 - CH2-

(a)

OH->NH2- >H-C≡C >CH3-CH2-

(b)

NH2->OH->CH3-CH2- >H-C≡C

(c)

CH3-CH2->NH2->H-C≡C->OH-

(d)

OH->H-C ≡ C->CH3-CH2- >NH2-

4. If the solubility product of lead iodide is 3.2 ×10-8 , its solubility will be

(a)

2×10-3M

(b)

4×10-4M

(c)

1.6 ×10-5M

(d)

1.8 ×10-5M

5. Pick the strongest conjugate base among the following

(a)

Cl-

(b)

${ NO }_{ 2 }^{ - }$

(c)

${ SO }_{ 4 }^{ 2- }$

(d)

CH3COO-

6. 5 x 2 = 10
7. Calculate the pH of 0.04 M HNO3 Solution.

8. Calculate the pH of 0.001M HCl solution

9. Calculate pH of 10-7M HCl

10. How is common ion effect related to the solubility of the electrolyte?

11. What are the limitations of Ostwald's dilution law?

12. 5 x 3 = 15
13. The Ka value for HCN is 10-9 . What is the pH of 0.4M HCN solution?

14. Derive an expression for the hydrolysis constant and degree of hydrolysis of salt of strong acid and weak base

15. A solution of 0.10M of a weak electrolyte is found to be dissociated to the extent of 1.20% at 25oC . Find the dissociation constant of the acid.

16. What is Henderson equation?

17. What do you mean by buffer action?

18. 2 x 5 = 10
19. A particular saturated solution of silver chromate Ag2 CrO4 has $[Ag^{+}]=5\times10^{-5}$ and $[CrO_{4}]^{2-}=4.4\times10^{-4}M$.What is the value of Ksp for Ag2 CrO4?

20. Write the expression for the solubility product of Hg2Cl2 .