Final answer:
Yes, a precipitate forms when iron II chloride is mixed with sodium sulfide; the precipitate is iron sulfide which is insoluble in water. Option A is correct.
Step-by-step explanation:
When iron II chloride (FeCl2) is mixed with sodium sulfide (Na2S), they undergo a double displacement reaction, and the products of this reaction include iron sulfide (FeS) and sodium chloride (NaCl). Iron sulfide is insoluble in water and therefore forms a precipitate.
According to solubility rules, sulfides are generally insoluble except for those of alkali metals (such as sodium or potassium) and alkaline earth metals (excluding strontium, barium, and lead). Since iron is not an alkali or alkaline earth metal, the sulfide it forms is insoluble, confirming that a precipitate will form.
Iron(II) chloride and sodium sulfide will form a precipitate when mixed. The chemical equation for this reaction is:
FeCl2(aq) + Na2S(aq) → FeS(s) + 2NaCl(aq)
Iron(II) chloride reacts with sodium sulfide to produce iron(II) sulfide, which is insoluble in water and appears as a precipitate. Sodium chloride remains in the solution as it is soluble in water.