The dand fblock elements - Result Question 66
####66. Prussian blue is formed when
[1989]
(a) Ferrous sulphate reacts with $FeCl_3$
(b) Ferric sulphate reacts with $K_4[Fe(CN)_6]$
(c) Ferrous ammonium sulphate reacts with $FeCl_3$
(d) Ammonium sulphate reacts with $FeCl_3$
Show Answer
Solution:
- (b) Potassium ferrocyanide solution is added to $Fe^{3+}$ ions in solution to give deep blue solution or precipitate.
$ \begin{aligned} & 2 Fe_2(SO_4)_3+3 K_4[Fe(CN)_6] \longrightarrow \\ & Fe_4[Fe(CN)_6]_3+6 K_2 SO_4 \\ & \text{ Prussian blue } \end{aligned} $
