JEE Main202125 Feb 2021Morning ShiftChemistryThermodynamics (C)Actual
The ionization enthalpy of Na + formation from Na g is 495 . 8   kJ   mol - 1 , while the electron gain enthalpy of Br is - 325 . 0   kJ   mol - 1 . Given the lattice enthalpy of NaBr is - 728 . 4   kJ   mol   - 1 . The energy for the formation of NaBr ionic solid is - _ _ _ _ _ 10 - 1   kJ   mol - 1
Correct answer
5576
Step-by-step solution
ΔH formation   = IE 1 + ΔHeg 1 + LE = 495 . 8 + - 325 + - 728 . 4 = - 557 . 6 = - 5576 × 10 - 1 KJ / mol   . Note: The above calculation is not for ΔH formation   but for ΔH Reaction   But on the basis of given data it is the best ans.