d-Block Elements

The number of unpaired electrons in gaseous species of Mn³⁺, Cr³⁺ and V³⁺ respectively are

• 4, 4 and 2

• 3,3 and 2

• 4, 3 and 2

• 3,3 and 3

Zinc and mercury do not show variable valency like d-block elements because

• They are soft

• Their d-shells are complete

• they have only two electrons in the outermost subshell

• Their d-shells are incomplete

Which one of the following cyano complexes would exhibit the lowest value of paramagnetic behaviour?

(At. No. Cr = 24, Mn = 25, Fe = 26, Co = 27)

• [Cr(CN)₆]^3–

• [Mn(CN)₆]^3–

• [Fe(CN)₆]^3–

• [Co(CN)₆]^3–

What is the maximum oxidation state expected for vanadium?

• +5

• +6

• +4

• +2

What is the electron configuration of the Sc(I) ion?

• [Ar] 4s¹4d¹

• [Ar] 4s¹3d¹

• [Ar] 3s¹3d¹

• {Ar] 4d²

What is the electron configuration of the Ni(II) ion? At no: 28

• [Ar] 4s²3d⁶

• [Ar] 4s²3d⁸

• [Ar] 3d⁸

• [Ar] 4s¹3d⁷

Which of the metal ions in the following complex ions has a d⁵ electron configuration?

• V(H₂O)₆²⁺

• Co(CN)^-₄

• Mo(NH₃)₆³⁺

• Fe(CN)₆^3–

What are the oxidation numbers of each central metal atom in the following coordination compounds?

K₃[Fe(CN)₆], [Cr(NH₃)₄Br₂]Br, [Ni(H₂O)₆]Cl₂, Na₂[TaF₇]

• 3, 3, 3, 5

• -3, 3, 3, 5

• 3, 3, 2, 5

• 3, 3, 2, 7

State the electronic configuration for the Fe2+ cation. Atomic number of iron :26

• [Ar]3d⁴

• [Ar]3d⁶

• [Ar]3d²

• [Ar]3d⁷

 

The oxidation state of Cr in [Cr(NH₃)₄Cl₂]⁺ is

• +3

• +2

• 0

• 1