Q. No.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.
HCl is not used to make the medium acidic in oxidation reaction of , because
| 1. | Both HCl and KMnO4 act as oxidising agents. |
| 2. | KMnO4 oxidises HCl into Cl2, which is also an oxidising agent. |
| 3. | KMnO4 is a weaker oxidising agent than HCl. |
| 4. | KMnO 4 acts as a reducing agent in the presence of HCl. |
Which of the following compounds cannot act as an oxidising agent?
| 1. | \(\mathrm{CrO}_3 \) | 2. | \(\mathrm{CrO}_4^{2-} \) |
| 3. | \(\mathrm{WO}_3\) | 4. | Both 1 and 2 |
Match the properties given in Column I with the metals given in Column II:
| Column I - (Property) | Column II - (Metal) | ||
| A. | Element with highest second ionisation enthalpy | 1. | V |
| B. | Element with highest third ionisation enthalpy | 2. | Cr |
| C. | M in M(CO)6 is | 3. | Cu |
| D. | Element with the highest heat of atomisation | 4. | Zn |
| A | B | C | D | |
| 1. | 3 | 4 | 1 | 2 |
| 2. | 3 | 4 | 2 | 1 |
| 3. | 1 | 2 | 4 | 3 |
| 4. | 3 | 2 | 4 | 1 |
The oxidation state that cerium (Ce) most commonly exhibits are:
1. +2, +3
2. +2, +4
3. +3, +4
4. +3, +5
The correct order of decreasing second ionization enthalpy of Ti(22), V(23), Cr (24) and Mn(25) is :
1. Cr > Mn > V > Ti
2. V > Mn > Cr > Ti
3. Mn > Cr > Ti > V
4. Ti > V > Cr > Mn
Electronic configuration of a transition element X in +3 oxidation state is [Ar] 3d5. What is its atomic number?
1. 25
2. 26
3. 27
4. 24
Which of the following statements is true?
| 1. | Cu(II)aq is more stable. |
| 2. | Cu(II)aq is less stable. |
| 3. | Cu(I) and Cu(II) are equally stable. |
| 4. | Stability of Cu(I) and Cu(II) depends on nature of copper salts. |
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
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