Question

Pure anhydrous magnesium chloride can be prepared from hydrated salt by:

• A. heating the hydrate to red heat in the atmosphere of HCl gas
• B. melting the hydrate
• C. heating the hydrate with coke
• D. heating the hydrate with Mg ribbon

Answer 1

The correct option is A heating the hydrate to red heat in the atmosphere of HCl gas

The hydrated magnesium chloride is heated to red heat in presence of hydrogen chloride gas to obtain pure anhydrous magnesium chloride. Hydrogen chloride gas prevents the decomposition of magnesium chloride.