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

← JEE Main 2026 · 2 Apr · Shift 2

ChemistrySingle correct+4 / -1Question 60 of 75

Given below are two statements :

Statement I : Among Zn, Mn, Sc and Cu, the energy required to remove the third valence electron is highest for Zn and lowest for Sc.

Statement II : The correct order of the following complexes in terms of CFSE is $\ce{[Co(H2O)6]^{2+}} < \ce{[Co(H2O)6]^{3+}} < \ce{[Co(en)3]^{3+}}$ .

In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Statement I is false but Statement II is true

Answer and worked solution

Official answer: A

Statement I. Third ionisation enthalpies: Sc 2389 (gives the noble-gas core, lowest), Mn 3248, Cu 3555, Zn 3833 (breaks into $3d^{10}$ , highest): true.

Statement II. CFSE:

$\ce{[Co(H2O)6]^{2+}}$ : high-spin d⁷, small;
$\ce{[Co(H2O)6]^{3+}}$ : low-spin d⁶, larger;
$\ce{[Co(en)3]^{3+}}$ : low-spin d⁶ with the stronger ligand en, largest.

True.

(A)

Topics:Crystal field theory Transition element properties

← Previous question Next question →

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