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. |
A gas that can readily decolorize an acidified KMnO4 solution is:
| 1. | SO2 | 2. | NO2 |
| 3. | P2O5 | 4. | CO2 |
The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution will be:
1. +2
2. +3
3. +4
4. +6
:
Why does manganese show a maximum oxidation state of +4 in MnF₄ but reach +7 in Mn₂O₇?
| 1. | Fluorine is more electronegative than oxygen. |
| 2. | Fluorine does not possess d orbitals. |
| 3. | Fluorine stabilizes the lower oxidation state of Mn. |
| 4. | In covalent compounds, fluorine forms only single bonds while oxygen can form double bonds. |