MCQ
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 $(-)$ ........... $\times 10^{-1} kJ \,mol ^{-1}$
  • A
    $5581$
  • B
    $4856$
  • C
    $5596$
  • $5576$

Answer

Correct option: D.
$5576$
d
$\Delta H _{\text {formation }}= IE _{1}+\Delta Heg _{1}+ LE$

$=495.8+(-325)+(-728.4)$

$=-557.6$

$=-5576 \times 10^{-1} KJ / mol .$

Note: The above calculation is not for $\Delta H _{\text {formation }}$ but for $\Delta H _{ Reaction}$

But on the basis of given data it is the best ans.

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