Which one of the following first row transition elements is expected to have the highest third ionization enthalpy?

Question

Which one of the following first row transition elements is expected to have the highest third ionization enthalpy? (A) Vanadium (Z = 23) (B) Manganese (Z = 25) (C) Chromium (Z = 24) (D) Iron (Z = 26)

Tardigrade Admin · Accepted Answer

M2+ xrightarrow[-e-]IE3 M3+ Mn2+ has the most stable configuration, i.e., 3d5 (all the five d-orbitals are singly occupied). Hence, to remove electron from Mn2+ ion requires more energy, i.e., the third ionization enthalpy of manganese is highest.

Q. Which one of the following first row transition elements is expected to have the highest third ionization enthalpy?

Vanadium (Z = 23)

Manganese (Z = 25)

Chromium (Z = 24)

Iron (Z = 26)

$M^{2 +} I E_{3} - e^{-} M^{3 +}$
$M n^{2 +}$ has the most stable configuration, i.e., $3 d^{5}$ (all the five d-orbitals are singly occupied). Hence, to remove electron from $M n^{2 +}$ ion requires more energy, i.e., the third ionization enthalpy of manganese is highest.

Q. Which one of the following first row transition elements is expected to have the highest third ionization enthalpy?

Vanadium (Z = 23)

Manganese (Z = 25)

Chromium (Z = 24)

Iron (Z = 26)

M2+IE3​−e−​M3+ Mn2+ has the most stable configuration, i.e., 3d5 (all the five d-orbitals are singly occupied). Hence, to remove electron from Mn2+ ion requires more energy, i.e., the third ionization enthalpy of manganese is highest.

$M^{2 +} I E_{3} - e^{-} M^{3 +}$
$M n^{2 +}$ has the most stable configuration, i.e., $3 d^{5}$ (all the five d-orbitals are singly occupied). Hence, to remove electron from $M n^{2 +}$ ion requires more energy, i.e., the third ionization enthalpy of manganese is highest.