7. Oxides are formed when food is roasted. But why is it necessary to roast oxide ores? a) To avoid gangue particles b) To get crude metal with using oxidising agent c) To remove volatile impurities in the form of their oxides d) To make the ore porous
Answer: c Explanation: Roasting is used to eliminate volatile impurities in the form of oxides from oxide ores. Metals are easier to acquire (by reduction) from their oxides than from carbonates or sulphides. As a result, the ore must first be transformed to metal oxide before it can be reduced.
