Assuming complete ionization, same moles of which of the following compounds will require the least amount of acidified KMnO4 for complex oxidation?
1.
2.
3.
4.
A pair among the following have nearly the same atomic radii:
(Numbers in the parenthesis are atomic numbers).
Which of the following processes does not involve the oxidation of iron?
1. | Rusting of iron sheets |
2. | Decolourisation of blue CuSO4 solution by iron |
3. | Formation of Fe(CO)5 from Fe |
4. | Liberation of H2 from steam by iron at high temperature |
The pair of compounds that can exist together is:
1. FeCl3, SnCl2
2. HgCl, SnCl2
3. FeCl2, SnCl2
4. FeCl3, Kl
In acidic medium, H2O2 changes Cr2O7–2 to CrO5 which has two (–O – O–) bonds.
The oxidation state of Cr in CrO5 is:
1. +5
2. +3
3. +6
4. -10
The reason for the lanthanoid contraction is:
1. negligible screening effect of 'f' orbitals.
2. increasing nuclear charge.
3. decreasing nuclear charge.
4. decreasing screening effect.
Which of the following statements is false?
1. | On passing H2S through acidified K2Cr2O7 solution, a milky colour is observed. |
2. | Na2Cr2O7 is preferred over K2Cr2O7 in volumetric analysis. |
3. | K2Cr2O7 solution in an acidic medium is orange. |
4. | K2Cr2O7 solution becomes yellow in increasing the pH beyond 7 |