[pingpongerke]

Hi, i'm Belgian a student civil engineer in the first year and for our exam we have to know te Dow-proces and our prof quite often asks why MgCl₂ has to be dehydrated before it can be electrolysed.
I can't find the answer anywhere, at first I thought it would have been because water would be oxidized or reduced at one of the poles of the cell, but when I look up Mg and Cl in the table of reduction energy's they are above/under the reduction reactions of H₂O.
Can anyone help me with this?

(my excuses if I used somewhat strange Enlish)

[ARGOS++]

Dear Pingpongerke;

Magnesium has a Standard Reduction Potential  of  -2.38 Volt, and that’s significantly less then that of H⁺/H° (H3O⁺), so in an aqueous solution Hydrogen will be produced instead of Magnesium.
(see on table:  "Standard Reduction Potentials  in Aqueous Solution”)

Good Luck!
                    ARGOS⁺⁺

[eugenedakin]

Excellent answer ARGOS++

Thankyou!

Eugene

[ARGOS++]

Dear Eugenedakin;

Thank you very much!    ─   
I think that are too, too much “Flowers” for just a very little knowledge.

Good Luck!
                    ARGOS⁺⁺