Iron `(+II)` is one of the most important oxidation states, and salts are called ferrous salts. Most of `Fe(+II)` salts are pale green and contain `[Fe(H_(2)O)_(6)]^(2+)` ion. `Fe(+II)` compounds are easily oxidised by air and so are difficult to obtain pure `Fe^(2+)` form many complexes like `K_(4)[Fe(CN)_(6)]`
Anhydrous `FeCl_(2)` is made by
A. heating Fe with dilute HCl
B. heating Fe with gaseous HCl
C. reacting Fe with conc. HCl
D. heating Fe with `Cl_(2)` gas