Question

Which of the following statements is incorrect ?

• A. In $K_4 [Fe (CN)_6]$ the ligand has satisfied both primary and secondary valencies of ferrous ion
• B. In $[Cu (NH_3 )_4] SO_4$, the ligand has satisfied only the secondary valency of copper
• C. In $K_3 [Fe(CN)_6 ]$ , the ligand has satisfied only the secondary valency of ferric ion
• D. In $K_3 [Fe(CN)_6]$, the ligand has satisfied both primary and secondary valencies of ferric ion

Answer 1

Answer: (C)

$K _{3}\left[ Fe ( CN )_{6}\right]$
$x-6=-3$
$x=-3+6$
$x=6$
$C N=6 \rightarrow$ primary valency.
for $+3$ Fe oxid $^{n}$ state it will Stability secondary valency