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Why does iron pyrite have formula FeS2 though the valency of iron is 2, 3, and that of sulphur is 2?
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Oscar Candelas
Why does iron pyrite have formula FeS2 though the valency of iron is 2, 3, and that of sulphur is 2?
Because it's not two separate S[math]^{-2}[/math] sulfide ions - think of it instead as a single S[math]_2^{-2}[/math]persulfide ion, which has two S atoms each with a formal charge of -1 and joined by a covalent bond: [math]^-[/math]S-S[math]^-[/math].
Because it's not two separate S[math]^{-2}[/math] sulfide ions - think of it instead as a single S[math]_2^{-2}[/math]persulfide ion, which has two S atoms each with a formal charge of -1 and joined by a covalent bond: [math]^-[/math]S-S[math]^-[/math].
Because in iron pyrite, the sulfur does not have an oxidation number of -2. It is in the form of a disulfide, the sulfur analog of peroxide. So you have an S[math]_2^{2-}[/math] ion (with a single bond between the sulfurs) and an Fe[math]^{2+}[/math] ion.
Because in iron pyrite, the sulfur does not have an oxidation number of -2. It is in the form of a disulfide, the sulfur analog of peroxide. So you have an S[math]_2^{2-}[/math] ion (with a single bond between the sulfurs) and an Fe[math]^{2+}[/math] ion.
Because it's not two separate S[math]^{-2}[/math] sulfide ions - think of it instead as a single S[math]_2^{-2}[/math] persulfide ion, which has two S atoms each with a formal charge of -1 and joined by a covalent bond: [math]^-[/math]S-S[math]^-[/math].
Because it's not two separate S[math]^{-2}[/math] sulfide ions - think of it instead as a single S[math]_2^{-2}[/math] persulfide ion, which has two S atoms each with a formal charge of -1 and joined by a covalent bond: [math]^-[/math]S-S[math]^-[/math].
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Because in iron pyrite, the sulfur does not have an oxidation number of -2. It is in the form of a disulfide, the sulfur analog of peroxide. So you have an S[math]_2^{2-}[/math] ion (with a single bond between the sulfurs) and an Fe[math]^{2+}[/math] ion.
Because in iron pyrite, the sulfur does not have an oxidation number of -2. It is in the form of a disulfide, the sulfur analog of peroxide. So you have an S[math]_2^{2-}[/math] ion (with a single bond between the sulfurs) and an Fe[math]^{2+}[/math] ion.
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