The metallic radii of some transition elements are given below. An element that has the highest density is:
Element | Fe | Co | Ni | Cu |
Metallic radii/pm | 126 | 125 | 125 | 128 |
1. Fe
2. Ni
3. Co
4. Cu
The electronic configuration of gadolinium (atomic number of 64) is:
1.
2.
3.
4.
Match Column I (Catalyst) with Column II (Process), and mark the appropriate option:
Column I - (Catalyst) | Column II - (Process) | ||
A. | Ni in the presence of hydrogen | 1. | Contact process |
B. | Cu2Cl2 | 2. | Vegetable oil to ghee |
C. | V2O5 | 3. | Sandmeyer reaction |
D. | Finely divided iron | 4. | Haber's process |
5. | Decomposition of KClO3 |
Codes:
A | B | C | D | |
1. | 3 | 4 | 2 | 5 |
2. | 2 | 3 | 1 | 4 |
3. | 5 | 4 | 3 | 2 |
4. | 4 | 5 | 3 | 2 |
Highest oxidation state of manganese in fluoride is +4 (Mn) but the highest oxidation state in oxides is +7 (Mn2O7). The reason is :
1. | Fluorine is more electronegative than oxygen. |
2. | Fluorine does not possess d orbitals. |
3. | Fluorine stabilizes lower oxidation state of Mn. |
4. | In covalent compounds, fluorine can only form a single bond while oxygen forms a double bond. |
Among the following, which are amphoteric oxides?
1. V2O5, Cr2O3
2. Mn2O7, CrO3
3. CrO, V2O5
4. V2O5, V2O4
Urea reacts with water to form A, which decomposes to form B. When B is passed through (aq), a deep blue-colored solution C is formed
The formula of C is:
2.
3.
4.
Colourless ion among the following is:
1. | Cr+4 | 2. | Sc+3 |
3. | Ti+3 | 4. | V+3 |
An element among the following that exhibits the maximum oxidation state is:
1. Cr
2. Mn
3. Fe
4. V
Match the following characteristics to the appropriate metal:
Column I - Aspects | Column II - Metal | ||
(a) | The metal which reveals the maximum number of oxidation states | (i) | Scandium |
(b) | The metal although placed in 3d block is considered not 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 :
(a) | (b) | (c) | (d) | |
1. | (i) | (iv) | (ii) | (iii) |
2. | (iii) | (iv) | (i) | (ii) |
3. | (iii) | (i) | (iv) | (ii) |
4. | (ii) | (iv) | (i) | (iii) |
Mn2+ compounds are more stable than Fe2+ compounds towards oxidation in their +3 state because :
1. | 3d5 configuration is more stable than 3d6 configuration. |
2. | 3d6 configuration is more stable than 3d5 configuration. |
3. | 3p5 configuration is less stable than 3p6 configuration. |
4. | 3p6 configuration is less stable than 3p5 configuration. |