Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of:
1. | Lanthanoid contraction |
2. | Having similar chemical properties |
3. | Belonging to the same group |
4. | Diagonal relationship |
The incorrect statement among the following is:
1. | Lanthanoids are good conductors of heat and electricity. |
2. | Actinoids are highly reactive metals, especially when finely divided. |
3. | Actinoid contraction is greater for element to element than Lanthanoid contraction. |
4. | Most of the trivalent Lanthanoid ions are colorless in the solid-state. |
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+
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 catalytic activity of transition metals is due to:
1. | High enthalpy of atomization |
2. | Paramagnetic behaviour |
3. | Colour of hydrated ions |
4. | Variable oxidation states |
An incorrect statement among the following is :
1. | La(OH)3 is less basic than Lu(OH)3 |
2. | In Lanthanide series, ionic radius of Ln+3 ions decreases. |
3. | La is an element of a transition and not of Lanthanide series. |
4. | The atomic radius of Zr and Hf are the same because of Lanthanide contraction. |
Zn gives H2 gas with H2SO4 and HCl but not with HNO3 because:
1. | Zn acts as an oxidizing agent when it reacts with HNO3 |
2. | HNO3 is weaker acid than H2SO4 and HCl |
3. | In the electrochemical series, Zn is above hydrogen |
4. | NO3Θ is reduced in preference to hydronium ion. |
An element among the following that shows the maximum number of oxidation states is:
1. Cr
2. Fe
3. Mn
4. V
The general electronic configuration of lanthanoids is:
1. (n – 2) f 1–14 (n – 1) s2 p6 d0–1 ns2
2. (n – 2) f 10–14 (n – 1) d0–1 ns2
3. (n – 2) f 0–14 (n – 1) d10 ns2
4. (n – 2) d0–1 (n – 1) f 1–14 ns2
A set of ions among the following that have a 3d2 electronic configuration is:
1.
2.
3.
4.