Which of the following is amphoteric oxide ?
1. | 2. | ||
3. | 4. |
Gadolinium (atomic number 64) belongs to the 4f series.
The correct electronic configuration of gadolinium among the following is:
\(1. (X e) 4 f^{7} 5 d^{1} 6 s^{2} \)
2. \( (X e) 4 f^{6} 5 d^{2} 6 s^{2}\)
3. \((X e) 4 f^{8} 6 d^{2}\)
4. \((X e) 4 f^{9} 5 s^{1}\)
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
1. | They have high melting points in comparison to pure metals |
2. | They are very hard |
3. | They are conductor. |
4. | They are chemically very reactive |
The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of ion is:
1. | 2.87 BM | 2. | 3.87 BM |
3. | 3.47 BM | 4. | 3.57 BM |
KMnO4 acts as an oxidising agent in alkaline medium. When alkaline KMnO4 is treated with KI, iodide ion is oxidised to .........
1. | \( I_{2}\) | 2. | \( I O^{-}\) |
3. | \( I O_{3}^{-}\) | 4. | \(I O_{4}^{-}\) |
Which of the following statements is not correct?
1. | Copper liberates hydrogen from acids |
2. | In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine |
3. | are oxidising agents in an aqueous solution |
4. | are reducing agents in an aqueous solution |
When acidified the solution is added to Sn++ salt then Sn++ changes to
1. | Sn | 2. | Sn3+ |
3. | Sn4+ | 4. | Sn+ |
Highest oxidation state of manganese in fluoride is +4(Mn) but highest oxidation state in oxides is +7() because
1. | Fluorine is more electronegative than oxygen |
2. | Fluorine does not possess d orbitals |
3. | Fluorine stabilises lower oxidation state |
4. | In covalent compounds, fluorine can form single bond only while oxygen forms double bond |
Although zirconium belongs to 4d transition series and hafnium to 5d transition series even then they show similar physical and chemical properties because............. .
1. | Both belong to d-block |
2. | Both have same number of electrons |
3. | Both have similar atomic radius |
4. | Both belong to the same group of the Periodic Table |
Why is HCl not used to make the medium acidic in oxidation reactions of in acidic medium?
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. | KMnO4 acts as a reducing agent in the presence of HCl |