The correct statement(s) about transition elements is/are:
1. | The lowest oxide of a transition metal is basic, the highest is amphoteric/acidic. |
2. | A transition metal exhibits the highest oxidation state in oxides and fluorides. |
3. | The highest oxidation state is exhibited in the oxoanions of a metal. |
4. | All of the above. |
1. | Cr2+ is strongly oxidizing while manganese(III) is strongly reducing. |
2. | Cobalt(II) is stable in an aqueous solution but in the presence of complexing reagents, it is easily oxidized. |
3. | The d1 configuration is very unstable in ions. |
4. | None of the above. |
The value for copper is positive (+0.34 V), because
1. | Copper has a high energy of atomization and a low hydration energy |
2. | Copper has low energy of atomization and high hydration energy. |
3. | Copper has equal energy of atomization and hydration energy. |
4. | None of the above. |
The correct trend for I.E1 (1st Ionization Enthalpy) in the 3d series is:
1. | Ionisation energy regularly decreases on moving along the period. |
2. | Ionisation energy regularly increases on moving along the period. |
3. | An irregular trend is observed for ionization energy because of electronic configuration. |
4. | None of the above. |
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. |
1. | The number of oxidation states increases on moving from Sc to Mn. |
2. | The relative stability of the +2 oxidation state increases on moving from top to bottom. |
3. | The relative stability of the +2 oxidation state decreases on moving from top to bottom. |
4. | Both (1) and (2) |
For M2+/M, and M3+/M2+, the values of some metals are given in the table below:
Cr+2/Cr = -0.9 V | Cr+3/Cr+2 = -0.4V |
Mn+2/Mn = -1.2V | Mn+3/Mn+2 = +1.5 V |
Fe+2/Fe = -0.4V | Fe+3/Fe+2 = +0.8 V |
The correct inference(s) from the above data is/are:
1. | The increasing order of their stability is Mn3+< Fe3+< Cr3+ |
2. | The increasing order of the above-mentioned metals ability to get oxidized is: Fe < Cr < Mn |
3. | The increasing order of the above-mentioned metals ability to get oxidized is: Fe > Cr > Mn |
4. | Both 1 and 2 |
Incorrect statement(s) regarding inner transition elements is/are:
1. | Lanthanoid contraction has a stronger impact on the radius than actinoid contraction |
2. | Lanthanoids commonly show +4 oxidation state |
3. | Actinoids are more reactive metals than lanthanoids. |
4. | Both (1) and (2) |
The most common oxidation state for lanthanoids and actinoids is:
1. | +5 | 2. | –3 |
3. | +1 | 4. | +3 |