The enthalpy of atomization of transition metals is high due to :
1. High effective nuclear charge
2. A large number of valence electrons
3. Very strong metallic bonds
4. All of the above
The transition metals generally form coloured compounds due to :
1. | Absorption of radiation to promote an electron . |
2. | Presence of ligands, the d-orbitals split up into two sets of orbitals. |
3. | Energy required to promote an electron in d subshell is low. |
4. | All of the above. |
Transition metals and their many compounds act as good catalysts due to :
1. | Variable oxidation states | 2. | Unstable intermediate |
3. | Provide a suitable surface | 4. | All of the above |
Transition metals show paramagnetic behaviour due to:
1. Paired electrons in the (n-1) d-orbitals
2. Unpaired electrons in the (n-1) d-orbitals
3. Due to \(d^{10},\) and \(d^{0}\) configuration
4. None of the above
The correct statement(s) about interstitial compounds is/are:
1. | Transition elements are large in size and contain multiple interstitial sites. |
2. | Transition elements can trap atoms of other elements. |
3. | Interstitial compounds are chemically inert. |
4. | All of the above. |
Match the following:
Ions | Number of unpaired electrons |
i. Mn3+ | a. 2 |
ii. Cr3+ | b. 4 |
iii. V3+ | c. 1 |
iv. Ti3+ | d. 3 |
i | ii | iii | iv | |
1. | c | d | b | a |
2. | b | d | a | c |
3. | d | b | a | c |
4. | b | d | c | a |
The correct statement(s) about transition elements are:
1. | +2, and +3 oxidation states are more common for elements in the first transition series, while higher oxidation states are more common for the heavier elements. |
2. | The heavier transition elements form low-spin complexes only. |
3. | The atomic sizes of the elements of the first transition series are smaller than those of the heavier elements (elements of 2nd and 3r transition series). |
4. | All of the above. |
The most common oxidation state for lanthanoids and actinoids is:
1. | +5 | 2. | –3 |
3. | +1 | 4. | +3 |
The correct statement(s) regarding the oxidation state of transition elements is/are:
1. The oxidation state can vary from +1 to +7
2. Variable oxidation states are possible.
3. Both (1) and (2)
4. None of the above
The reaction(s) involved in the preparation of potassium dichromate from iron chromite ore is/are:
1. | FeCr2O4 + NaOH + O2 → Na2CrO4 + Fe2O3 + H2O |
2. | Na2CrO4 + H2SO4 (conc.) → Na2Cr2O7 + Na2SO4 + H2O |
3. | Na2Cr2O7 + KCl→ K2Cr2O7 + NaCl |
4. | All of the above. |