Question

The chemical formula of cassiterite is:
$\begin{align}
A. & PbS{{O}_{4}} \\
B.& Sn{{O}_{2}} \\
C. & Pb{{O}_{2}} \\
D. & \text{None of these} \\
\end{align}$

Answer 1

Hint:The name Cassiterite is derived from the Greek word ‘kassiteros’ which means tin.Out of all the types of ores of tin that are found today, the largest percentage of those is occupied by cassiterite.

Complete step by step answer:
Let us now analyse cassiterite as a chemical compound and its possible applications in everyday life.
-Cassiterite is a tin oxide mineral, \[Sn{{O}_{2}}\]. It is generally black or reddish brown and opaque, but it is translucent in thin crystals. Its lustre and multiple crystal faces produce a desirable gem. It is colourless when pure although very rare, and brown or black when iron impurities are present. Commercially important quantities occur in beds of rivers or lakes, but it can also be found in granite and pegmatites.
-Tin is extracted from cassiterite by roasting the ore with carbon in a furnace to approximately $2500{}^\circ F$. The following reaction takes place in the furnace:
\[Sn{{O}_{2}}+2C\to Sn+2CO\]
-In the next step the tin is drained away from the soil and ash using filters, this process is also called leaching, with acid or water solutions to remove all the remaining impurities. Heavy metal impurities can be removed using electrostatic or magnetic separation. Limestone is added to produce a slag with the impurities, which can be separated physically.

Therefore, the answer to this question is ‘B) $Sn{{O}_{2}}$’.

Note:
Small amounts of primary cassiterite are found in igneous and metamorphic rocks throughout the world. It is also a residual mineral found in soils and sediments. Cassiterite is more resistant to weathering than many other minerals. Due to this, concentrations of it can be found in stream and shoreline sediments.