Question

Describe why there is a different between the formulae of both ionic salt i.e NaCl and MgCl?

Answer 1

Well, sodium metal is oxidized to a `"Group 1 cation"`, i.e. `Na^+`..., an alkali metal cation....with a SINGLE positive charge....

Explanation:

And magnesium forms a `"Group 2 dication"`, i.e. `Mg^(2+)`..., an alkaline earth dication....and this is strictly in accord with the simple electronic structure we deduce from the Periodic Table: sodium has one valence electron; and magnesium has two valence electrons. You grab?

And so for electric neutrality after oxidation of the metal, while sodium ion must draft in one equiv of chloride ion to give a neutral salt...i.e.

`Na^+ + Cl^(-) rarrNaCl`

...magnesium dication must draft in TWO EQUIV of halide counterion...i.e.

`Mg^(2+) + 2Cl^(-) rarrMgCl_2`..

...and so your question, if that is how it was presented to you, is improperly proposed. Both the given reactions conserve mass and charge, as indeed they must do if they represent an actual chemical process. Do you appreciate what I mean in the given context?

Answer 2

Well, they are different salts after all...

Explanation:

`NaCl` and `MgCl` are neutralized salts formed after a neutralization reaction. The first salt, sodium chloride `(NaCl)`, can be formed by mixing hydrochloric acid `(HCl)` and sodium hydroxide `(NaOH)` together. The second salt, magnesium chloride `(MgCl)` can be formed by mixing together hydrochloric acid `(HCl)` and magnesium hydroxide `(Mg(OH)_2)`.

They are both ionic salts. But, they are made of different metals.