AEC3323 SEM II 2024/2025 QUIZ 2 (14 MAY 2025)

Give the chemical formula of diaquobis(ethylenediamine)chromium(II) ion.

• [Cr(en)₂(H₂O)₂]²⁺

• [Cr(en)₂(H₂O)]²⁺

• [Cr(NH₃)₂(H₂O)₂]²⁺

• [Cr(NH₃)₂(H₂O)]²⁺

Transition metals typically have incompletely filled d subshells. Among the elements below, identify the metal that not belong to this category.

• Ni

• Cu

• Ag

• Hg

Predict the number of unpaired spins in the [Cr(en)₃]²⁺ ion.

• 4 unpaired spins

• 3 unpaired spins

• 2 unpaired spins

• 1 unpaired spins

The ion [Co(NH₃)₆]²⁺ is octahedral and high spin.  This complex is paramagnetic, with 1 unpaired electron.

• TRUE

• FALSE

Calculate the spin-only magnetic moment for Cr atom.

• 1.7 µ_B

• 2.8 µ_B

• 5.9 µ_B

• 6.9 µ_B

In a square planar metal complex, which of the orbitals is highest energy?

• d_xz

• d_x2-y2

• d_yz

• d_xy

A coordination compound with a magnetic moment of 5.1 Bohr magnetons has 4 unpaired electrons for this compound.

• FALSE

• TRUE

Identify the most transition metal M in K₃[M(CN)₆], which M is a first row transition metal and the complex has 3 unpaired electrons.

• Cr

• Mn

• Fe

• Co

Give the electron configuration of Cu²⁺.

(Z = 29)

• [Ar] 4s¹ 3d⁸

• [Ar] 3d⁹

• [Ar] 3d⁸

• [Ar] 3d⁷

Specify the coordination number (C.N) and oxidation number (O.N) of the metal atom in the [Co(NH₃)₂(H₂O)₂Cl₂]⁺.

• C.N. = 6; O.N. = +1

• C.N. = 6; O.N. = +2

• C.N. = 4; O.N. = +3

• C.N. = 6; O.N. = +3