Question

Black tin is _____________
A.An alloy of $Sn$
B.An allotrope of $Sn$
C.60-70 percent $Sn{O_2}$
D.100 percent $Sn{O_2}$

Answer 1

Hint:
Black tin is an ore of tin which is smelted and then refined for use. Tin is a chemical element which is black in colour and is found near river banks in ores. It is represented by Sn and has an atomic number of 50. $Sn{O_2}$ is known as cassiterite which is considered as the main ore for tin.

Complete step by step answer:
Tin is a chemical element which is represented by $Sn$ and has an atomic number of 50. It is usually black in colour. Black tin is an ore of tin which is smelted and then refined for further use. $Sn{O_2}$ is Tin(IV) oxide which is also known as cassiterite and is the main ore of tin thus, all the ores of tin contain $Sn{O_2}$. Tin dioxide is an inorganic compound and has tetragonal structure. It is insoluble in water because it does not form hydrogen bonds with water. It is colourless and amphoteric in nature.
Tin dioxide is the main ore for extraction of tin and black tin is also an ore of tin and cassiterite covers about 60-70% composition of black tin. Also it is known as an oxygen-deficient n-type semiconductor.
So, the answer for the above question is option (C) 60-70% $Sn{O_2}$
Black tin is 60-70% $Sn{O_2}$ .

Note: Tin dioxide has various applications like acting as a catalyst for oxidation of various compounds and is also used for polishing and coating. Carbon monoxide is a very harmful gas as it replaces oxygen from our blood and tin dioxide is used as a detector for carbon monoxide.