The equation 4HNO3 + 2FeS -> 2Fe(NO3)3 + 2H2O + 4NO + SO2

Detailed information about the compounds:

• HNO₃: is nitric acid, a strong acid commonly used in chemistry and industry. HNO₃ has strong oxidizing properties.
• FeS: Iron sulfide, is a compound of iron and sulfur.
• Fe(NO3)3: Iron(III) nitrate, a compound of iron and nitrate.
• H2O: Water.
• NO: Nitric oxide, a colorless, odorless gas that is toxic.
• SO₂: Sulfur dioxide, a pale yellow gas with a pungent smell and is toxic.

Reaction condition:

This reaction requires high temperature to occur.

Reaction process:

In this reaction, nitric acid reacts with iron sulfide to form iron(III) nitrate, water, nitric oxide and sulfur dioxide.

Observed phenomena:

When the reaction occurs, there will be a phenomenon of gas rising, at the same time there is a pungent smell due to the formation of SO₂ and NO gas. When the reaction ends, we can see the formation of iron(III) nitrate in the form of brown precipitate.