Anhydrous `MgCl_(2)` can be prepared by :

Options

A. heating `MgCl_(2).6H_(2)O(s)`
B. heating `MgCl_(2).6H_(2)O(s)` in dry HCl atmosphere at `175^(@)`
C. heating KCl.`MgCl_(2).6H_(2)O`
D. all of the above

Answer

B

Explanation

Hydrated chloride on heating gets hydrolysed.
`{:(MgCl_(2).6H_(2)O overset(Delta)rarr Mg (OH) Cl overset(Delta)rarr MgO+HCl),(" "darrHCl),(" " MgCl_(2)+H_(2)O):}`