Question

the term 3 fecl₂ in a balanced equation says a that there are three iron(ii) ions and two chloride ions bonded together. b that there are three iron(ii) ions and 6 chloride ions bonded together. c that there are three formula units, each consisting of two chloride ions bonded to an iron(ii) ion. d that there are three particles, each consisting of three iron atoms and 6 chlorine atoms.

Explanation:

• Analyze each option:
• Option A: Each $\ce{FeCl_{2}}$ has 1 $\ce{Fe^{2+}}$ and 2 $\ce{Cl^-}$. For 3 $\ce{FeCl_{2}}$, it's 3 $\ce{Fe^{2+}}$ and 6 $\ce{Cl^-}$, not 2 $\ce{Cl^-}$ total. Eliminate A.
• Option B: "Bonded together" is incorrect. $\ce{FeCl_{2}}$ is an ionic compound, and the formula unit represents the ratio, not bonded ions in a single unit as described. Eliminate B.
• Option C: Each $\ce{FeCl_{2}}$ formula unit has 1 $\ce{Fe}$ and 2 $\ce{Cl}$. So 3 formula units have 3 $\ce{Fe}$ (as $\ce{Fe^{2+}}$) and 6 $\ce{Cl}$. This matches the correct interpretation of the coefficient (3) and the formula subscripts.
• Option D: Each $\ce{FeCl_{2}}$ has 1 $\ce{Fe}$, not 3. Eliminate D.

Answer:

C. that there are three formula units, each consisting of two chloride ions bonded to an iron(II) ion.