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 number of d -electrons in Fe2+ (atomic number Z = 26) is different from the number of:
1. s-electrons in Mg (Z = 12)
2. p-electrons in Cl (Z = 17)
3. d-electrons in Fe (Z = 26)
4. p-electrons in Ne (Z = 10)
The pair of compounds that can exist together is:
1. FeCl3, SnCl2
2. HgCl, SnCl2
3. FeCl2, SnCl2
4. FeCl3, Kl
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 |
For the four successive transition elements (Cr, Mn, Fe and Co), the stability of +2 oxidation state will be there in which of the following order?
(At. No Cr= 24, Mn= 25, Fe=26, Co= 27)
1. Fe>Mn>Co>Cr
2. Co>Mn>Fe>Cr
3. Cr>Mn>Co>Fe
4. Mn>Fe>Cr>Co