Question

Question #99468

Answer 1

In an aqueous solution the compound `MgCl_2` will separate into 1 `mg^+2` ion and 2 `F^-1` ions.

Explanation:

In the compound `MgF_2` The electron density is concentrated around the Florine atoms. This is because Florine has the highest electronegativity of any element and Magnesium has one of the lowest electronegativities. This causes the formation of ionic bonds. om

The ionic bonds become separated in an aqueous solution. The polar covalent bonding of the water molecules pull the ionic bonds apart. The Florine atoms with the greatest electron density are surrounded by the Hydrogen side of the water molecule separating the Florine atom from the Magnesium atom creating two Florine -1 ions.

The Magnesium atom with very little electron density attracts the Oxygen side of the water which has a partial negative charge. This causes the Magnesium atom to separate from the Florine atom and creates a Magnesium +2 ion.

Answer 2

It's all in the transfer of electrons from `"Mg"` to `"F"`.

Explanation:

We can imagine the reaction taking place in two steps.

First, a fluorine molecule separates into two fluorine atoms:

`"F"_2 → "F + F"`

Each `"F"` atom has seven valence electrons. It can get an octet by gaining one more electron.

A `"Mg"` atom has two valence electrons. It can get to an octet by losing two electrons.

The `"Mg"` atom will donate its electrons to to the two `"F"` atoms to form stable `"Mg"^"2+"` and `"F"^"-"` ions.

Note: It takes energy to break the `"F-F"` bond, but that is more than compensated by the attractions among the newly-formed `"Mg"^"2+"` and `"F"^"-"` ions.