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. |
Match the following aspects with the respective metal.
Aspects | Metal | ||
(a) | The metal which reveals the maximum number of oxidation states | (i) | Scandium |
(b) | The metal although placed in a 3d block is not considered as a transition element | (ii) | Copper |
(c) | The metal which does not exhibit variable oxidation states | (iii) | Manganese |
(d) | The metal which in +1 oxidation state in aqueous solution undergoes disproportionation | (iv) | Zinc |
Select the correct option:
Options: | (a) | (b) | (c) | (d) |
1. | (i) | (iv) | (ii) | (iii) |
2. | (iii) | (iv) | (i) | (ii) |
3. | (iii) | (i) | (iv) | (ii) |
4. | (ii) | (iv) | (i) | (iii) |
Identify the incorrect statement from the following:
1. | Zirconium and Hafnium have identical radii of 160 pm and 159 pm, respectively as a consequence of lanthanoid contraction. |
2. | Lanthanoids reveal only +3 oxidation state. |
3. | The lanthanoid ions other than the f0 type and the f14 type are all paramagnetic. |
4. | The overall decrease in atomic and ionic radii from lanthanum to lutetium is called lanthanoid contraction. |
1. | High basic character | 2. | Small size |
3. | High exchange enthalpy | 4. | High electronegativity |
1. | +6 to +5 | 2. | +7 to +4 |
3. | +6 to +4 | 4. | +7 to +3 |
Match the statements given in List-I with the corresponding element given in List-II:
List-I | List-II | ||
(a) | Element that exhibits +3 oxidation state only. | (i) | Mn |
(b) | An element that exhibits more number of oxidation states. | (ii) | Zn |
(c) | Element which is a reducing agent in its +2 oxidation state. | (iii) | Sc |
(d) | An element that is not considered as a transition element. | (iv) | Cr |
(a) | (b) | (c) | (d) | |
1. | (iii) | (iv) | (i) | (ii) |
2. | (iv) | (i) | (ii) | (iii) |
3. | (ii) | (iv) | (iii) | (i) |
4. | (iii) | (i) | (iv) | (ii) |
Identify the pair of Lanthanoides with one strong oxidant and one strong reductant:
1. | Ce(IV), Tb(IV) | 2. | Yb(II), Eu(II) |
3. | Eu(IV), Lu(III) | 4. | Ce(IV), Eu(II) |
1. | 4f orbitals are penultimate |
2. | 4f orbitals have a greater shielding effect |
3. | 5f orbitals have a poor shielding effect |
4. | 5f orbitals have a greater shielding effect |
Statement I: | Cr2+ is oxidising agent and Mn3+ is a reducing agent in nature. |
Statement II: | Sc3+ compounds are repelled by the applied magnetic field. |
1. | Both I and II are correct. |
2. | Both I and II are incorrect. |
3. | I is correct but II is incorrect. |
4. | I is incorrect but II is correct. |