d- and f-Block Elements

In which of the following pairs are both the ions coloured in aqueous solution? (At. no. : Sc = 21, Ti = 22, Ni = 28, Cu = 29, Co = 27)

1. Ni2+, Cu+
2. Ni2+, Ti3+
3. Sc3+, Ti3+
4. Sc3+, Co2+.

Copper sulphate dissolves in excess of KCN to give

1. Cu(CN)2
2. CuCN
3. [Cu(CN)4]3-
4. [Cu(CN)4]2-

More number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is

1. more active nature of the actinoids
2. more energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
3. lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
4. greater metallic character of the lanthanoids than that of the corresponding actinoids.

More number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is

1. more active nature of the actinoids
2. more energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
3. lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
4. greater metallic character of the lanthanoids than that of the corresponding actinoids.

The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is

1. one
2. two
3. five
4. one fifth

Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionisation enthalpy?

1. Vanadium (Z = 23)
2. Chromium (Z = 24)
3. Manganese (Z = 25)
4. Iron (Z = 26)

The aqueous solution containing which one of the following ions will be colourless? (Atomic number : Sc = 21, Fe = 26, Ti = 22, Mn = 25)

1. Sc3+
2. Fe2+
3. Ti3+
4. Mn2+

Among K, Ca, Fe and Zn, the element which can form more than one binary compound with chlorine is

1. Fe
2. Zn
3. K
4. Ca

Among the following series of transition metal ions, the one where all metal ions have 3d2 electronic configuration is [At. Nos. Ti = 22, V = 23, Cr = 24, Mn = 25]

1. Ti3+, V2+, Cr3+, Mn4+
2. Ti+, V4+, Cr6+, Mn7+
3. Ti4+, V3+, Cr2+, Mn3+
4. Ti2+, V3+, Cr4+, Mn5+

Lanthanoids are

1. 14 elements in the sixth period (atomic no. 90 to 103) that are filling 4f sublevel
2. 14 elements in the seventh period (atomic number = 90 to 103) that are filling 5f sublevel
3. 14 elements in the sixth period (atomic number = 58 to 71) that are filling the 4f sublevel
4. 14 elements in the seventh period (atomic number = 50 to 71) that are filling 4f sublevel.

Which one of the following characteristics of the transition metals is associated with their catalytic activity?

1. High enthalpy of atomization
2. Paramagnetic behaviour
3. Colour of hydrated ions
4. Variable oxidation states

The basic character of the transition metal monoxides follows the order (Atomic nos. Ti = 22, V = 23, Cr = 24, Fe = 26)

1. VO > CrO > TiO > FeO
2. CrO > VO > FeO > TiO
3. TiO > FeO > VO > CrO
4. TiO > VO > CrO > FeO

The correct order of ionic radii of Y3+, La3+, Eu3+ and Lu3+ is (Atomic nos. Y = 39, La = 57, Eu = 63, Lu = 71)

1. Y3+ < La3+ < Eu3+ < Lu3+
2. Y3+ < Lu3+ < Eu3+ < La3+
3. Lu3+ < Eu3+ < La3+ < Y3+
4. La3+ < Eu3+ < Lu3+ < Y3+

General electronic configuration of lanthanides is

1. (n-2)f1-14 (n-1)s2p6d0-1 ns2
2. (n-2)f0-14 (n-1)d0-1 ns2
3. (n-2)f0-14 (n-1)d10 ns2
4. (n-2)d0-1 (n-1)f1-14 ns2

Which of the following shows maximum number of oxidation states?

1. Cr
2. Fe
3. Mn
4. V

Which of the following statements is not correct?

1. La(OH)3 is less basic than Lu(OH)3.
2. In lanthanide series ionic radius of Ln3+ ion decreases.
3. La is actually an element of transition series rather than lanthanides.
4. Atomic radii of Zr and Hf are nearly the same because of lanthanide contraction.

Which of the following shows maximum number of oxidation states?

1. Cr
2. Fe
3. Mn
4. V

Which ion is colourless?

1. Cr4+
2. Sc3+
3. Ti3+
4. V3+