Among the following, which are amphoteric oxides?
1. V2O5, Cr2O3
2. Mn2O7, CrO3
3. CrO, V2O5
4. V2O5, V2O4
The correct value of the spin-only magnetic moment of ion is equal to:
1. | 2.87 BM | 2. | 3.87 BM |
3. | 3.47 BM | 4. | 3.57 BM |
Which of the following statements is false?
1. | Copper liberates hydrogen from acids. |
2. | In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine. |
3. | Mn3+, and Co3+ are oxidizing agents in an aqueous solution. |
4. | Ti2+, and Cr2+ are reducing agents in an aqueous solution. |
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