According to Werner's theory,the primary valency of a central metal ion is:

Which of the following are examples of double salts?
$A$. $FeSO_4 \cdot (NH_4)_2SO_4 \cdot 6H_2O$
$B$. $CuSO_4 \cdot 4NH_3 \cdot H_2O$
$C$. $K_2SO_4 \cdot Al_2(SO_4)_3 \cdot 24H_2O$
$D$. $Fe(CN)_2 \cdot 4KCN$
Choose the correct answer.

In which of the following compounds is the oxidation state of $Fe$ zero?

$A$ solution of potassium ferrocyanide would contain $.......$ ions.

Which one of the following is not an ambidentate ligand?

The molecular formula of potash alum is