Question

Is `"Mg"^(2+)` a Lewis Acid or Lewis Base?

Answer 1

Well, it's a cation, so........

Explanation:

So, reasonably it should be an electron pair acceptor, and thus a Lewis acid. And while we write `Mg^(2+)`, in water we also write `Mg^(2+)(aq)`, by which we mean `[Mg(OH_2)_6]^(2+)`, which is, if you like, a coordination complex of `Mg^(2+)`.

In ether and THF, the magnesium centre is also solvated in this way.