Question

Prussian blue is a deep blue pigment containing $F{e}^{2+},F{e}^{3+}$ and $C{N}^{-}$ ions. It has the formula ${\left(Fe\right)}_7{\left(CN\right)}_{18}$ . How many $F{e}^{2+}$ and $F{e}^{3+}$ ions are there per formula unit?

• A. $3F{e}^{2+}$ and $4F{e}^{3+}$
• B. $4F{e}^{2+}$ and $3F{e}^{3+}$
• C. $5F{e}^{2+}$ and $2F{e}^{3+}$
• D. $6F{e}^{2+}$ and $1F{e}^{3+}$

Answer 1

Answer: (A)

Prussian blue is a deep blue pigment is $F{e}_4{\left[Fe(CN{)}_6\right]}_3$