How do you prepare anhydrous iron chloride?

Anhydrous iron(II) chloride (FeCl₂) can be prepared by reacting iron powder with hydrochloric acid in methanol, followed by heating in a vacuum.

Here's a breakdown of the process:

1. Reaction of Iron with Hydrochloric Acid in Methanol:

   • Iron powder is added to a solution of hydrochloric acid (HCl) in methanol (CH₃OH).
   • This reaction produces the methanol solvate of iron(II) chloride (FeCl₂).
   • The chemical equation for this step is: Fe + 2 HCl → FeCl₂ + H₂

2. Vacuum Heating:

   • The methanol solvate of iron(II) chloride is then heated in a vacuum.
   • This heating process removes the methanol molecules, resulting in anhydrous iron(II) chloride.
   • The heating is typically carried out at approximately 160 °C.

Therefore, the two-step process effectively produces anhydrous FeCl₂.