Strontium carbonyl ferrocyanide, Sr₃[Fe(CN)₅CO]₂

Strontium carbonyl ferrocyanide, Sr₃[Fe(CN)₅CO]₂.4H₂O, may be prepared in a similar manner to the barium salt. It is a yellow hygroscopic powder, which becomes anhydrous at 200° C. The heats of solution are as follow: -

[Sr₃(Fe(CN)₅CO)₂] + Aq. = Sr₃(Fe(CN)₅CO)₂.Aq. + 39,900 calories,
[Sr₃(Fe(CN)₅CO)₂.4H₂O)] + Aq. = Sr₃(Fe(CN)₅CO)₂.Aq. + 32,400 calories,

whence the heat of hydration of the anhydrous salt at 13.3° C. is 7500 calories.