Dow's process of extraction of Mg involves extraction of Mg from sea water. Sea water is concentrated in sun-light and is then treated with slaked lime. Magnesium hydroxide is heated in a stream of HCl to give MgCl_(2) which is electrolysed to discharge Mg. The mixture is in the ratio 35% MgCl_(2)+50% NaCl+15% CaCl_(2). NaCl and CaCl_(2) are added to lower the fusion temperature and to increases the conductance. Mg^(2+) +Ca(OH)_(2) to Mg(OH)_(2)+Ca^(2+) Mg(OH)_(2)+2HCl to MgCl_(2)+2H_(2)O(l) Electrolysis of fused MgCl_(2) hArr Mg^(2+)+2Cl Mg^(2+)+2e^(-) to Mg( At Cathode) 2Cl^(-) to Cl_(2)+2e^(-) (At Anode) Mg electrolysed is protected from atmospheric oxidation by a blanket of inert gases. Molten mixutre of NaCl and CaCl_(2) is added to the heated MgCl_(2) because :

Dow's process of extraction of Mg involves extraction of Mg from sea w

1.	Dow's process of extraction of Mg involves extraction of Mg from sea water. Sea water is concentrated in sun-light and is then treated with slaked lime. Magnesium hydroxide is heated in a stream of HCl to give MgCl_(2) which is electrolysed to discharge Mg. The mixture is in the ratio 35% MgCl_(2)+50% NaCl+15% CaCl_(2). NaCl and CaCl_(2) are added to lower the fusion temperature and to increases the conductance. Mg^(2+) +Ca(OH)_(2) to Mg(OH)_(2)+Ca^(2+) Mg(OH)_(2)+2HCl to MgCl_(2)+2H_(2)O(l) Electrolysis of fused MgCl_(2) hArr Mg^(2+)+2Cl Mg^(2+)+2e^(-) to Mg( At Cathode) 2Cl^(-) to Cl_(2)+2e^(-) (At Anode) Mg electrolysed is protected from atmospheric oxidation by a blanket of inert gases. Molten mixutre of NaCl and CaCl_(2) is added to the heated MgCl_(2) because :
Answer» `MgCl_(2). xH_(2)O+ " DRY " HCl overset(973-1223K) to ` Partially dehydrated `MgCl_(2)` and molten mixture `(NACL+CaCl_(2))` makes it fully dehydrated `CaCl_(2)` is dehydrating agent `(CaCl_(2)+ NaCl)` lowers the MELTING point of `MgCl_(2)` None of these Answer :C