(a) Determine the oxidation number of manganese in MnO(_4)
(b)(i) List two metals that are extracted from their ores by electrolysis
(ii) Give one difference between a conductor and an electrolyte.
Explanation
(a) X + (4X – 2) = -1
X – 8 = -1
X = +8 – 1 = +7
(b)(i) Aluminium or calcium or sodium or potassium or magnesium.
(ii)
| Conductors | Electrolytes |
|
(1) They are not decomposed by electric current Decomposed by the passage of current. (2) They are usually solids (3) Free electrons conduct the current |
Decomposed by the passage of current They are molten or aqueous solution Mobile ions conduct the current. |