JEE Main · 2025 · Shift-IhardPERI-138

An element 'E' has the ionisation enthalpy value of 374 kJ mol-1. 'E' reacts with elements A, B, C and D with electron…

Classification of Elements & Periodicity · Class 11 · JEE Main Previous Year Question

Question

An element 'E' has the ionisation enthalpy value of 374 kJ mol1^{-1}. 'E' reacts with elements A, B, C and D with electron gain enthalpy values of 328-328, 349-349, 325-325 and 295-295 kJ mol1^{-1}, respectively.

The correct order of the products EA, EB, EC and ED in terms of ionic character is:

Options
  1. a

    EB>EA>EC>EDEB > EA > EC > ED

  2. b

    ED>EC>EA>EBED > EC > EA > EB

  3. c

    EA>EB>EC>EDEA > EB > EC > ED

  4. d

    ED>EC>EB>EAED > EC > EB > EA

Correct Answera

EB>EA>EC>EDEB > EA > EC > ED

Detailed Solution

🧠 More exothermic EGE → more stable anion → more ionic compound Ionic character of a compound between E and a non-metal depends on how strongly the non-metal attracts the electron. A more negative EGE means the anion is more stable, and the bond is more ionic.

🗺️ Rank by EGE magnitude Element E has IE=374IE = 374 kJ/mol (very low — a highly electropositive metal, likely Cs or Rb).

  • B: 349-349 kJ/mol — most exothermic. Most stable anion. Most ionic compound (EB).
  • A: 328-328 kJ/mol.
  • C: 325-325 kJ/mol.
  • D: 295-295 kJ/mol — least exothermic. Least ionic.

Order of ionic character: EB>EA>EC>EDEB > EA > EC > ED.

Answer: (a)\boxed{\text{Answer: (a)}}

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An element 'E' has the ionisation enthalpy value of 374 kJ mol-1. 'E' reacts with elements A, B, C… (JEE Main 2025) | Canvas Classes