Question

When iron pyrite burnt, the gas evolved is:
A. ${O_2}$
B. $C{O_2}$
C. $S{O_2}$
D. ${H_2}S$

Answer 1

Hint: Burning is the process in which a substance is burnt in air in the presence of oxygen gas. The molecular formula of iron pyrite is $Fe{S_2}$. It is also known as iron sulfide. It has an unique metallic luster and pale brass yellow colour due to which people call it fool’s gold.

Complete step by step answer:
We already know that burning of iron pyrite means iron pyrite will be reacting with oxygen. When iron pyrite reacts with oxygen the $Fe$and $S$will get oxidised to $F{e_2}O_3^{}$and $S{O_2}$respectively. The chemical reaction can be written as $Fe{S_2} + {O_2} \to F{e_2}{O_3} + S{O_2}$.
The balanced chemical equation will be $4Fe{S_2} + 11{O_2} \to 2F{e_2}{O_3} + 8S{O_2}$, so from this reaction we can understand that sulphur dioxide gas is been released.

Hence option C is correct.

Additional information:
 Iron pyrite is the most abundant sulfide mineral .It is also known as fool’s gold because of it’s metallic luster and pale brass yellow colour. It can be dangerous because it contaminates the groundwater due to acid mine drainage from sulphide mine tailings. The iron pyrite is more prone to corrosion as compared to gold and silver. Many goldsmiths and jewellery makers try to fool people because of it’s metallic luster and pale brass yellow colour, due to which it looks like gold.

Note:
Always remember that the molecular formula of iron pyrite is $Fe{S_2}$. Whenever we burn iron pyrite in the presence of oxygen we get sulphur dioxide and ferric oxide as products. The balanced chemical reaction can be written as $4Fe{S_2} + 11{O_2} \to 2F{e_2}{O_3} + 8S{O_2}$.