JEE Main 2026 · 6 Apr · Shift 2 · Chemistry Q60

ChemistrySingle correct+4 / -1Question 60 of 75

The correct order of first ( $\Delta_iH_1$ ) and second ( $\Delta_iH_2$ ) ionisation enthalpy values of Cr and Mn are :

A. $\Delta_iH_1$ : Cr > Mn

B. $\Delta_iH_2$ : Cr > Mn

C. $\Delta_iH_1$ : Mn > Cr

D. $\Delta_iH_2$ : Mn > Cr

Choose the correct answer from the options given below :

A and B only

B and C only

A and D only

C and D only

Answer and worked solution

Official answer: B

First ionisation. Cr ( $3d^54s^1$ ) is 653 and Mn ( $3d^54s^2$ ) is 717 kJ/mol, so Mn > Cr (C).

Second ionisation. It removes an electron from Cr's stable $3d^5$ , but only the second 4s electron from Mn: Cr 1592 > Mn 1509 kJ/mol (B).

Correct: B and C.

(B)

Topics:Transition element properties

JEE Main 2026 · 6 Apr · Shift 2, Chemistry question 60