Common Mistakes to Avoid in INC-06

Confusing calcination and roasting: Calcination uses limited/absent air (for carbonates/hydrated ores); roasting uses excess air (for sulphide ores). Both produce metal oxides but by different conditions. The most common NEET trap is applying calcination to sulphide ores — wrong.
Misidentifying the Ellingham diagram direction: The 2C + $O_{2}$ → 2CO line slopes downward (more negative $\Delta G$ °) with temperature. Students often write it slopes upward. The C + $O_{2}$ → C $O_{2}$ line is nearly flat.
Thinking the lower Ellingham line is less stable: Lower line = more negative $\Delta G$ ° = more stable oxide = that metal does NOT get reduced easily. Confusing stability direction is a frequent error.
Mixing up anode and cathode in electrolytic refining: Impure metal is the anode (dissolves); pure metal is the cathode (deposits). Anode mud collects less electropositive metals (Au, Ag).
Forgetting that carbon anodes are consumed in Hall-Heroult: $O^{2-}$ reacts with carbon at the anode forming C $O_{2}$ . This is regularly tested.
Confusing Mond process temperatures: Formation of Ni(CO)_{4} at lower temperature (330–350 K); decomposition at higher temperature (450–470 K). Students swap these.
Assuming all minerals are ores: An ore must be economically extractable. Bauxite is an ore of Al; but $AlCl_{3}$ found in minute traces is just a mineral.
NaCN role confusion: NaCN is a depressant (suppresses ZnS), not a collector. Pine oil is the collector. Do not interchange these roles.
Blister copper purity: Blister copper is ~98% pure, not 100%. It requires further electrolytic refining to reach electrical grade.
Van Arkel vs Mond: Van Arkel uses iodide (Ti, Zr); Mond uses carbonyl (Ni). Do not mix the two processes or the metals.