4.Ion Exchange

*नोट: यह सेक्शन रिवीजन के लिए है। अपना ज्ञान परखने के लिए ऊपर दिए गए क्विज़ में भाग लें।

1. What type of process is Ion Exchange?
   A) Reversible  |  B) Irreversible  |  C) Slow  |  D) Only biological
2. An element carrying an electrical charge is called an:
   A) Atom  |  B) Molecule  |  C) Ion  |  D) Mineral
3. Cation Exchange is primarily a part of which soil action?
   A) Internal  |  B) Surface reaction  |  C) Gaseous  |  D) Destructive
4. How many main types of ion exchange occur in soil?
   A) One  |  B) Two (Cation and Anion exchange)  |  C) Three  |  D) Five
5. What is the standard international unit for measuring Cation Exchange Capacity (CEC)?
   A) meq/100g  |  B) cmol (+)/kg  |  C) Pascal  |  D) Meter/second
6. What are negatively charged ions called?
   A) Cations  |  B) Anions  |  C) Electrons  |  D) Protons
7. On which surfaces does cation exchange primarily occur in soil?
   A) Only on sand  |  B) Clay and Humus particles  |  C) Only on gravel  |  D) Only in air
8. Which ion predominates in Alkaline Soils?
   A) H+  |  B) Ca++  |  C) Na+ (Sodium)  |  D) Al+++
9. How do plants and microbes obtain Adsorbed Cations?
   A) Easily  |  B) With great difficulty  |  C) Never  |  D) Only from rain
10. The total capacity to adsorb cations on the soil complex is called:
    A) Base saturation  |  B) Cation Exchange Capacity (CEC)  |  C) Buffering  |  D) Water capacity
11. By what other name is Anion Exchange known?
    A) Base exchange  |  B) Acid exchange  |  C) Alkali exchange  |  D) None
12. What is the average CEC of organic matter (Humus)?
    A) 10-20  |  B) 50-80  |  C) 200 (100-300) cmol/kg  |  D) 4
13. On which theory is the mechanism of cation exchange based?
    A) Electrokinetic theory  |  B) Darwin theory  |  C) Sedimentation theory  |  D) Leaching theory
14. How does the CEC of soil change as the pH increases?
    A) Decreases  |  B) Gradually increases  |  C) Remains unchanged  |  D) Becomes zero
15. The capacity to hold anions increases with the ________ of the soil.
    A) Alkalinity  |  B) Acidity  |  C) Neutrality  |  D) Moisture
16. The fraction of total CEC occupied by major exchangeable bases (Ca, Mg, K, Na) is:
    A) Unsaturation  |  B) Percent Base Saturation  |  C) Ionic concentration  |  D) Displacement
17. How does increasing organic matter affect the CEC of soil?
    A) Decreases  |  B) Increases  |  C) No effect  |  D) Zeroes out
18. If the base saturation of a soil is 80%, the remaining 20% is saturated with which ions?
    A) Na and K  |  B) Ca and Mg  |  C) H and Al ions  |  D) Only Fe
19. Why is the pH of soils in tropical regions usually low (acidic)?
    A) Due to leaching of bases by heavy rain  |  B) Due to high sunlight  |  C) Due to lack of plants  |  D) None
20. Which is considered the single best indicator of Soil Fertility?
    A) Soil color  |  B) Soil depth  |  C) Cation Exchange Capacity (CEC)  |  D) Amount of gravel
21. What is primarily used to reclaim Acidic soils?
    A) Gypsum  |  B) Lime  |  C) Salt  |  D) Urea
22. How is the rate of exchange when the concentration of cations in soil solution is high?
    A) Low  |  B) More  |  C) Equal  |  D) Zero
23. In normal fertile soils, 'Calcium' constitutes what percentage of total exchangeable cations?
    A) 10-20%  |  B) 40%  |  C) 60 to 80 percent  |  D) 95%
24. How is the CEC of Clay loam soil compared to Sandy loam?
    A) Less  |  B) High  |  C) Equal  |  D) Negligible
25. Soil becomes ________ when exchangeable sodium (Na) exceeds 10-15% of CEC.
    A) Acidic  |  B) Neutral  |  C) Alkaline  |  D) Saline
26. What is the average CEC of Kaolinite mineral?
    A) 3-15 (Avg 8) cmol/kg  |  B) 60-100  |  C) 150  |  D) 200
27. What is the average CEC of Montmorillonite mineral?
    A) 8  |  B) 30  |  C) 80 (60-100) cmol/kg  |  D) 200
28. Which ion is NOT included in exchangeable bases of soil?
    A) Ca++  |  B) Mg++  |  C) H+ (Hydrogen)  |  D) Na+
29. What is the correct formula for calculating Percent Base Saturation (V)?
    A) V = S/T x 100  |  B) V = T/S x 100  |  C) V = S+T  |  D) V = 100/S
30. Which mineral has a CEC higher than Illite but lower than Montmorillonite due to Potassium (K) in its structure?
    A) Kaolinite  |  B) Vermiculite  |  C) Oxide  |  D) Gypsum
31. Which ion predominates in extremely acidic soils?
    A) Ca++  |  B) Al(OH)2+ (Aluminum ion)  |  C) Na+  |  D) K+
32. In normal fertile soil, exchangeable bases occupy approximately what percentage of CEC?
    A) 20-30%  |  B) 50%  |  C) 80 to 90 percent  |  D) 100%
33. Soil whose colloidal complex is saturated with exchangeable Ca++ ions is called:
    A) Base saturated soil  |  B) Base unsaturated soil  |  C) Acidic soil  |  D) None
34. What is the range of CEC for Illite mineral?
    A) 3-15  |  B) 20-40 cmol/kg  |  C) 100-200  |  D) 300-400
35. What is the average CEC of Vermiculite?
    A) 8  |  B) 80  |  C) 150 cmol/kg  |  D) 4
36. What does Anion Exchange in soil depend on?
    A) Only temperature  |  B) pH-dependent function  |  C) Only air  |  D) None
37. Adsorbed hydrogen ________ increases H+ ion concentration in soil solution.
    A) Indirectly  |  B) Directly  |  C) Not at all  |  D) Slowly
38. What does a soil CEC of 10 cmol/kg mean regarding 1 kg of soil?
    A) Adsorbs 1 cmol  |  B) Adsorbs 10 cmol H+ ions  |  C) Adsorbs 100 cmol  |  D) Adsorbs 0.1 cmol
39. What is the average CEC of Oxides and Hydroxides?
    A) 4 cmol/kg  |  B) 40  |  C) 100  |  D) 200
40. How does the ion exchange process affect fertilizer performance in soil?
    A) Fertilizers are destroyed  |  B) Availability of nutrients is regulated  |  C) No effect  |  D) Soil becomes toxic