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Revision of chapter Hydrogen for JEE Advanced

💯 Hydrogen Chapter Revision Q&A for JEE Advanced

  1. Q: What is the electron configuration of hydrogen?
    A: 1s1.
  2. Q: What is the bond length of the H2 molecule?
    A: Approximately 0.74 Ã….
  3. Q: What type of bond is present in H2 molecule?
    A: A sigma covalent bond formed by overlap of 1s orbitals.
  4. Q: What is the bond dissociation energy of H2?
    A: Approximately 436 kJ/mol.
  5. Q: What is isotopes of hydrogen?
    A: Protium, deuterium, and tritium.
  6. Q: What is the main use of deuterium?
    A: Heavy water (D2O) used as moderator in nuclear reactors.
  7. Q: How is hydrogen prepared in laboratory?
    A: Reaction of Zn with dilute H2SO4.
  8. Q: Industrial method of hydrogen production?
    A: Water gas reaction and steam methane reforming.
  9. Q: What is the reaction of hydrogen with oxygen?
    A: 2H2 + O2 → 2H2O (highly exothermic).
  10. Q: What is hydrogen’s oxidation state in H2O?
    A: +1.
  11. Q: Which is more stable, ortho-hydrogen or para-hydrogen?
    A: Para-hydrogen is more stable at low temperature.
  12. Q: What are hydrogen bonds?
    A: Attractive forces between hydrogen attached to electronegative atoms and lone pair of another electronegative atom.
  13. Q: In which compounds hydrogen bonding is strongest?
    A: HF molecules.
  14. Q: What is the structure of hydrogen molecule in ground state?
    A: Both electrons are paired in bonding sigma orbital.
  15. Q: What is hydride ion?
    A: H−, hydrogen with extra electron.
  16. Q: What are hydrides?
    A: Binary compounds of hydrogen with metals or non-metals.
  17. Q: Classify hydrides.
    A: Ionic, covalent, and interstitial hydrides.
  18. Q: Give an example of ionic hydride.
    A: NaH, CaH2.
  19. Q: Give an example of covalent hydride.
    A: CH4, NH3.
  20. Q: Give an example of interstitial hydride.
    A: TiH2.
  21. Q: Which hydrides are good reducing agents?
    A: Ionic hydrides.
  22. Q: What is reaction of hydrogen with nitrogen?
    A: Forms ammonia under Haber’s process.
  23. Q: State Haber process conditions.
    A: 200 atm, 450-500 °C, Fe catalyst.
  24. Q: What is the role of catalyst in Haber process?
    A: Lowers activation energy for N2 fixation.
  25. Q: What is the bond order in H2 molecule?
    A: 1.
  26. Q: Why hydrogen has high ionization energy?
    A: Small size and one proton binding one electron strongly.
  27. Q: How is hydrogen stored industrially?
    A: In high-pressure cylinders or in metal hydrides.
  28. Q: What is the electronic formula of hydrogen atom?
    A: 1s1.
  29. Q: What is ortho and para hydrogen?
    A: Ortho hydrogen has parallel spins; para has antiparallel spins.
  30. Q: Which form of hydrogen is paramagnetic?
    A: Ortho-hydrogen.
  31. Q: What is the color of hydrogen gas?
    A: Colorless.
  32. Q: What is the smell of hydrogen?
    A: Odorless.
  33. Q: What is the flammability of hydrogen?
    A: Highly flammable.
  34. Q: What is the molecular weight of hydrogen?
    A: 2 g/mol.
  35. Q: How does hydrogen react with halogens?
    A: Forms hydrogen halides.
  36. Q: What are hydrogen halides?
    A: HX compounds like HCl, HF.
  37. Q: What is acid strength order among hydrogen halides?
    A: HI > HBr > HCl > HF.
  38. Q: Which hydrogen halide is most reactive?
    A: HF bonds are strong but HF is less reactive as acid.
  39. Q: What is polarity of H–H bond?
    A: Nonpolar covalent bond.
  40. Q: Why does hydrogen exhibit both oxidizing and reducing properties?
    A: Can lose or gain one electron easily.
  41. Q: What is the atomic number of hydrogen?
    A: 1.
  42. Q: What is nuclear spin of hydrogen?
    A: 1/2.
  43. Q: What is the standard hydrogen electrode (SHE)?
    A: Electrode based on hydrogen gas electrode, reference for redox potential.
  44. Q: What is the oxidation state of hydrogen in metal hydrides?
    A: –1.
  45. Q: What is the bond dissociation energy of H–H?
    A: Approximately 436 kJ/mol.
  46. Q: What is the effect of temperature on equilibrium in Haber process?
    A: High temperature favors backward decomposition.
  47. Q: Which hydrogen isotope is radioactive?
    A: Tritium (³H).
  48. Q: How is tritium produced?
    A: By neutron bombardment of lithium or heavy water in nuclear reactors.
  49. Q: What is the use of tritium?
    A: As tracer in biochemical research and nuclear fusion fuel.
  50. Q: What is Brownian motion of hydrogen?
    A: Visible rapid random motion due to small mass.
  51. Q: What is the most abundant isotope of hydrogen?
    A: Protium (¹H).
  52. Q: Does hydrogen have allotropes?
    A: Yes, ortho and para hydrogen.
  53. Q: What is the molecular orbital configuration of H2?
    A: (σ1s)² only bonding orbital filled.
  54. Q: What is the bond order of H2?
    A: 1.
  55. Q: What is used as fuel in hydrogen fuel cells?
    A: Pure hydrogen gas.
  56. Q: What is the energy released by formation of one mole of H2 molecule?
    A: ~436 kJ/mol.
  57. Q: What do hydrides of nitrogen, phosphorus belong to?
    A: Covalent hydrides.
  58. Q: Which hydrides of group 1 is more ionic?
    A: Lithium hydride.
  59. Q: Can H2 act as a reducing agent?
    A: Yes, reduces metal oxides to metals.
  60. Q: What is the greenhouse effect of hydrogen?
    A: Negligible compared to other gases.
  61. Q: How is hydrogen detected in the laboratory?
    A: Burning produces a pop sound.
  62. Q: What is the density of hydrogen?
    A: 0.0899 g/L at STP.
  63. Q: What is the color and odor of hydrogen?
    A: Colorless and odorless.
  64. Q: What is the role of hydrogen in ammonia synthesis?
    A: Reacts with nitrogen to form NH3.
  65. Q: What is the electron affinity of hydrogen?
    A: 72.8 kJ/mol.
  66. Q: What happens if H2 is mixed with chlorine and exposed to light?
    A: It forms hydrogen chloride via radical chain reaction.
  67. Q: Which hydrogen isotope is used in nuclear fusion?
    A: Deuterium (²H) and Tritium (³H).
  68. Q: What is The main industrial use of hydrogen?
    A: Ammonia production, hydrogenation, refining.
  69. Q: What is ionic hydride characteristic?
    A: Formed with active metals; conducts electricity in molten state.
  70. Q: Which compound is source of hydrogen used in labs?
    A: Zn + dilute acid.
  71. Q: What type of energy is released when H–H bond breaks?
    A: Bond dissociation energy (endothermic).
  72. Q: What is the siofficient bond in H2?
    A: Sigma bond between 1s orbitals.
  73. Q: Hydrogen is placed in which group in periodic table?
    A: Group 1.
  74. Q: Is hydrogen a metal or non-metal?
    A: Non-metal.
  75. Q: Hydrogen shows properties of which groups?
    A: Alkali metals and halogens in some cases.
  76. Q: What is the melting point of hydrogen?
    A: −259.2 °C.
  77. Q: What is the boiling point of hydrogen?
    A: −252.87 °C.
  78. Q: What is the electron spin state of para-hydrogen?
    A: Spins are antiparallel (singlet).
  79. Q: What is the electron spin state of ortho-hydrogen?
    A: Spins are parallel (triplet).
  80. Q: Why is para-hydrogen more stable?
    A: Lower energy spin state with antiparallel spins.
  81. Q: What happens to ortho-hydrogen at very low temperature?
    A: It converts to para-hydrogen.
  82. Q: What is a temporary bonding state formed in H2 formation?
    A: Transition state.
  83. Q: What is the important use of hydrogen in petroleum industry?
    A: Hydrocracking and hydrogenation.
  84. Q: What is effect of hydrogen bonding on boiling point of water?
    A: Raises the boiling point significantly.
  85. Q: Which isotope of hydrogen is used as a tracer in chemical reactions?
    A: Deuterium.
  86. Q: What is standard electrode potential of hydrogen?
    A: 0 V (by definition).

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