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Give briefly the isolation of magnesium from sea water. Give equations for the steps involved. |
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Answer» In sea water, `MaCl` is present. `MgCl_(2) + Ca(OH)_(2) rarr Mg(OH)_(2) darr + CaCl_(2)` `underset ("Dry")(Mg(OH)_(2)) overset (Delta) rarr MgO + H_(2)O` `MgO + C + Cl_(2) overset (Delta) rarr MgCl_(2) + Co uarr` the anhydrous megnesium chloride is fused `NaCl` and anhydrous calcium chloride. The mixture is electrolysed at `700^@ C` in the presence of an inert gas in an electrolytic cell. Magnesium is discharged at the cathode. The purpose of the addition of `NaCl` and `CaCl_(2)` to anhydrous `MgCl_(2)` is to lower the fusion temperature and make fused mass a good conductor of electricity. Sodium chloride prevents the hydrolysis of magnesium chloride. `{:("At anode":,2Cl^(Ө)rarr Cl_(2) + 2e,,,),("At cathode":,Mg^(2+) + 2e^(Ө) rarr Mg,,,):}`. |
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