Question

Write chemical formula of Iron (III) hexacyanidoferrate (II).

Hint:

If a graph "touches" the x-axis (turns back) without crossing, it still counts as a zero (a repeated root). Always count every point where the graph meets the axis.

Answer 1

Concept:
Coordination compounds consist of a central metal ion surrounded by ligands. The name indicates oxidation states of metals and nature of ligands.
Given Name Breakdown:

Iron (III) → \(Fe^{3+}\)
Hexacyanidoferrate (II) → \([Fe(CN)_6]^{4-}\)
Charge Balance:
To form a neutral compound: \msg{LCM of charges = 12}
4 ions of \(Fe^{3+}\) → \(+12\)
3 ions of \([Fe(CN)_6]^{4-}\) → \(-12\)
Final Formula:
\[ Fe_4[Fe(CN)_6]_3 \] This compound is commonly known as
Prussian blue
. \[ \boxed{Fe_4[Fe(CN)_6]_3} \]