Extraction of Metals - Result Question 45

45. The carbon-based reduction method is not used for the extraction of

(2013 Adv.)

(a) tin from $SnO _2$

(b) iron from $Fe _2 O _3$

(c) aluminium from $Al _2 O _3$

(d) magnesium from $MgCO _3, CaCO _3$

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Answer:

Correct Answer: 45. (c, d)

Solution:

  1. Al has greater affinity for oxygen, hence oxide is not reduced by carbon. $MgO$ and $CaO$ (formed in the calcination from carbonates) are stable species and not reduced by carbon.

During Smelting $SnO _2+C \xrightarrow{1300^{\circ} C} Sn+CO$

$ 2 Fe _2 O _3+3 C \stackrel{\Delta}{\longrightarrow} 4 Fe+3 CO _2 $