Question
The correct order of decreasing second ionisation enthalpy of Ti (22), V (23), Cr(24) and Mn (25) is
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Cr > Mn> V > Ti
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V > Mn > Cr >Ti
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Mn > Cr> Ti >V
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Ti >V >Cr> Mn
Solution
A.
Cr > Mn> V > Ti
The amount of energy required to remove an electron from unipositive ions is called the second IP which generally increases in a period from left to right.
The second ionisation energies of the first transition series increase almost regularly with an increase in atomic number. However, the value for Cr is sufficiently higher than those of its neighbour ie, (Mn). This is due to the stable configuration of Cr3+ (3d5 exactly half filled.)
[Note: The half-filled and completely filled configuration are more stable.]
