Q. No.Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of:
1.
Lanthanoid contraction
2.
Having similar chemical properties
3.
Belonging to the same group
4.
Diagonal relationship
The incorrect statement among the following is:
| 1. | Lanthanoids are good conductors of heat and electricity. |
| 2. | Actinoids are highly reactive metals, especially when finely divided. |
| 3. | Actinoid contraction is greater for element to element than Lanthanoid contraction. |
| 4. | Most of the trivalent Lanthanoid ions are colourless in the solid-state. |
Consider the graph between enthalpies of atomization of transition elements vs atomic numbers:
The curve representing enthalpies of atomization for 3d series is
1. z
2. y
3. x
4. Cannot predict from the graph
Consider the following graph.
Based on the graph above, it can be concluded that the element with a melting point higher than 3000 K will be:
| 1. | Y | 2. | X |
| 3. | Z | 4. | None of the above |
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) |
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 |
| 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) |
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. |
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 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. |
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