Question

Tin is extracted from its ore, cassiterite, by:
A. Electrolytic reduction
B. Carbon monoxide reduction
C. Carbon reduction
D. The aluminothermic process

Answer 1

We know that tin is a metal. Metals are very hard, lustrous and good conductors of heat and electricity. Mostly metals are found in rocks which are called ores. But some elements are found as themselves which are said to be native. Some reducing agents are used to remove oxygen from the ore.

Complete step by step answer:
Generally, reactive metals are very difficult to extract from its ores. Reactive metals lie at the top of the reactivity series. Some examples are sodium, potassium, calcium, magnesium and aluminium. While those in the bottom of the reactivity series are least reactive metals. Some examples are gold, silver, copper etc. Moderately reactive metals lie at the middle of the reactivity series. Some examples are zinc, iron, lead, etc.
The ore of tin is cassiterite, ${\text{Sn}}{{\text{O}}_2}$ in which $78.8\%$ of the content is tin. Cassiterite is also known as tinstone. Cassiterite is heated at very high temperatures of about ${2500^\circ }{\text{F}}$ to get the pure metal by removing the oxygen. This process is known as smelting. Smelting is done by adding carbon in the form of coke or coal and limestone. Generally coke acts as a very good reducing agent and the ore gets reduced.
Hence tin is extracted from cassiterite by carbon reduction.

So, the correct option is C.

Note: There is another ore for tin, i.e. ${\text{C}}{{\text{u}}_2}{\text{SnFe}}{{\text{S}}_4}$. There is one more impurity in the ore of tin, i.e. iron. Thus it must also be removed. When the tin is extracted from its ore, i.e. cassiterite, tin oxide gets converted to tin and carbon to carbon dioxide.