Question

When fe(no3)2(aq) and na2s(aq) are mixed, what is the black coloured precipitate that forms?

Answer 1

The black colored precipitate formed when Fe(NO3)2(aq) and Na2S(aq) are mixed is Iron(II) sulfide, represented by the compound FeS.

Step-by-step explanation:

When Fe(NO3)2(aq) and Na2S(aq) are mixed, a precipitation reaction occurs. According to solubility rules, sulfides are generally insoluble, except for those of group 1 elements (like Na) and ammonium. Iron sulfide, which is not an exception to this rule, will precipitate as a solid. The black colored precipitate that forms is likely to be FeS (Iron(II) sulfide).

The relevant reaction can be represented by the ionic equation: Fe2+ (aq) + S2- (aq) → FeS (s), where the precipitate is the insoluble iron(II) sulfide.

While the information provided with the question includes several reactions and solubility examples, the key to answering this specific question is understanding the solubility of sulfides and that iron can form a black colored sulfide precipitate.

Answer 2

The black coloured precipitate that form is IRON ll SULPHIDE, FeS.
Iron sulphide ll sulphide is black in colour and is insoluble in water. It possess very high melting temperature and react in acids. Iron ll sulphide is used as pigment in hair dyes, glasses, bottles and paints. It is also used as lubricant.