12th Chemistry top 20 Repeated Five Marks

1. Repeated Most Frequently
2. Nernst Equation (Derivation/Explanation/Applications) → 7 times
   • “Derive Nernst equation”
   • “Explain Nernst equation”
   • “Calculate emf using Nernst equation”
   • “Derivation with application examples”
3. Distinguish Between Physisorption and Chemisorption → 5 times
   • “Differentiate Physisorption and Chemisorption”
   • “Explain their differences with examples”
4. Electrolytic Refining (Principle/Process) → 5 times
   • “Explain electrolytic refining with an example”
   • “Refining of silver, copper, etc.”
5. Froth Flotation (Process/Principle) → 4 times
   • “Explain Froth flotation process”
   • “Concentration of ores using Froth flotation”
6. Coordination Compounds and VB Theory → 4 times
   • “[Cr(NH₃)₆]³⁺ is paramagnetic, but [Ni(CN)₄]²⁻ is diamagnetic. Explain using VB theory.”
   • “Explain bonding in [Co(C₂O₄)₃]³⁻ using VB theory”
   • “Explain coordination compounds using VB theory”
7. Arrhenius Equation (Explanation/Derivation) → 4 times
   • “Write Arrhenius equation and explain its terms”
   • “Explain Arrhenius equation with reaction examples”
8. Differences Between Lanthanoids and Actinoids → 4 times
   • “Differentiate Lanthanoids and Actinoids”
   • “Write properties and uses of Lanthanoids and Actinoids”
9. Integrated Rate Law (Derivation/Explanation) → 4 times
   • “Derive the integrated rate law for a first-order reaction”
   • “Derive integrated rate law for a zero-order reaction”
10. Differentiate DNA and RNA. (2 marks)
11. Distinguish between DNA and RNA. (3 marks)
12. Explain the difference between DNA and RNA.
13. Difference between sigma and pi bonds – 3 times
14. Isotopes and isobars distinction – 3 times
15. Difference Between Order and Molecularity of a Reaction → 3 times
    • “Explain the difference between order and molecularity”
    • “Differentiate order and molecularity with examples”
16. Distinguishing Alcohols by Lucas Test → 3 times
    • “Explain Lucas test to distinguish alcohols”
    • “How to differentiate 1°, 2°, and 3° alcohols by Lucas test”
17. Aldol Condensation (Mechanism/Reaction) → 3 times
    • “Explain the mechanism of Aldol condensation”
    • “Write Aldol condensation with example”
18. Ostwald’s Dilution Law (Derivation/Definition) → 3 times
    • “Derive Ostwald’s dilution law”
    • “Define and explain Ostwald’s dilution law”
19. Zeolites (Properties/Uses) → 3 times
    • “Write a note on Zeolites”
    • “Explain the role of Zeolites in catalysis”
20. Interhalogen Compounds (Properties/Examples) → 2 times
    • “What are interhalogen compounds? Give examples”
    • “Write properties of interhalogen compounds”
21. Sacrificial Protection (Principle/Example) → 2 times
    • “Write a short note on sacrificial protection”
    • “Explain sacrificial protection with an example”
22. Lanthanide Contraction (Effects/Explanation) → 2 times
    • “Explain the effects of Lanthanide contraction”
    • “What is Lanthanide contraction? Why does it occur?”
23. Physical vs Chemical Adsorption (Differences) → 2 times
    • “Differentiate Physical and Chemical adsorption”
    • “Explain their differences with examples”
24. Structure of Diborane (Explanation/Properties) → 2 times
    • “Explain the structure of Diborane”
    • “Write the bonding in Diborane”
25. Common Ion Effect (Definition/Example) → 2 times
    • “Explain the common ion effect with an example”
    • “Write the application of common ion effect in salts”
26. Peptide Bond (Explanation/Properties) → 2 times
    • “Write a short note on peptide bond”
    • “Explain the structure and significance of peptide bonds”
27. Explain Swern Oxidation reaction with an example
28. What are ‘F’ centers?
29. What is Lucas reagent? Differentiate alcohols by Lucas test.
30. Why HF cannot be stored in glass bottles?
31. Write the structural formula for the following compounds:
    • Nitric acid
    • Dinitrogen pentoxide
    • Phosphoric acid
    • Phosphine
32. Write a note on antioxidants with an example
33. Explain the effects of enzyme catalysis on reaction rate
34. Explain the principle of Zone refining process
35. Give the preparation of Phosphine by using Caustic Soda
36. Explain the effects of catenation
37. Explain the Hall-Heroult process for refining aluminum
38. Explain Kolbe’s electrolytic decarboxylation
39. Describe the structure of glucose
40. Explain the properties and uses of acetic acid
41. Explain Gomberg reaction with mechanism
42. Write a note on electro-osmosis
43. Explain the preparation of Nylon 6,6
44. Write the formula of Zeise’s salt and Magnus’s green salt
45. Explain Valence Bond Theory of coordination compounds