Extraction of Crude Metal from Concentrated Ore — Prelims Strategy
Prelims Strategy
To excel in NEET questions on 'Extraction of Crude Metal from Concentrated Ore,' a systematic approach is essential. Firstly, master the definitions and distinctions between calcination and roasting, paying close attention to the type of ore (carbonate/hydroxide vs.
sulfide) and the atmospheric conditions (absence vs. presence of air). Secondly, memorize the key reactions for each process, including the main reactants, products, and any significant by-products (like from calcination or from roasting).
Thirdly, understand the choice of reducing agents based on the metal's reactivity and the stability of its oxide. Know when to use carbon/CO, when to use more reactive metals (Aluminothermic process), and when electrolytic reduction is necessary.
Fourthly, grasp the concept of flux and slag formation, identifying common acidic and basic fluxes and the types of gangue they remove. For numerical problems (though rare here), ensure you can balance chemical equations.
When tackling MCQs, carefully read the question to identify keywords like 'excess air,' 'absence of air,' 'sulfide ore,' 'carbonate ore,' 'reducing agent,' or 'flux.' Eliminate options that contradict these keywords.
Pay attention to trap options that might swap conditions or ore types between calcination and roasting. Regular revision of the reactions and their conditions will build strong recall.