The correct order of decreasing second ionisation enthalpy of Ti(22), V (23), Cr (24) and Mn (25) is

Step-by-step solution

Key Idea : The amount of energy required to remove an electron from a unipositive ion is called 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 increase in atomic number. However, the value for Cr is sufficiently higher than those of its neighbour, ie, (Mn). This is due to stable configuration of Cr ⁺ ( 3 d^5 exactly half filled). Note : The halffilled and completely filled configurations are more stable