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.
2.
3.
4.
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
Highest oxidation state of manganese in fluoride is +4 (Mn) but the highest oxidation state in oxides is +7 (Mn2O7). The reason is :
1. | Fluorine is more electronegative than oxygen. |
2. | Fluorine does not possess d orbitals. |
3. | Fluorine stabilizes lower oxidation state of Mn. |
4. | In covalent compounds, fluorine can only form a single bond while oxygen forms a double bond. |