Question

properties of mgcl2 and why

Answer 1

First, do you know what MgCl2 is?

Answer 2

I'll take that as a "no.." Well, It's Magnesium Chloride. Magnesium chloride is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water. The hydrated magnesium chloride can be extracted from brine or sea water. In North America, magnesium chloride is produced primarily from Great Salt Lake brine. It is extracted in a similar process from the Dead Sea in the Jordan valley. Magnesium chloride, as the natural mineral bischofite, is also extracted (via solution mining) out of ancient seabeds; for example, the Zechstein seabed in northwest Europe. Some magnesium chloride is made from solar evaporation of seawater. Anhydrous magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form most readily available.

Answer 3

MgCl2 crystallizes in the cadmium chloride motif, which features octahedral Mg. A variety of hydrates are known with the formula MgCl2(H2O)x, and each loses water with increasing temperature: x = 12 (−16.4 °C), 8 (−3.4 °C), 6 (116.7 °C), 4 (181 °C), 2 (ca. 300 °C). In the hexahydrate, the Mg2+ remains octahedral, but is coordinated to six water ligands. The thermal dehydration of the hydrates MgCl2(H2O)x (x = 6, 12) does not occur straightforwardly.

As suggested by the existence of some hydrates, anhydrous MgCl2 is a Lewis acid, although a very weak one.

In the Dow process, magnesium chloride is regenerated from magnesium hydroxide using hydrochloric acid:

Mg(OH)2(s) + 2 HCl → MgCl2(aq) + 2 H2O(l)
It can also be prepared from magnesium carbonate by a similar reaction.

In most of its derivatives, MgCl2 forms octahedral complexes. Derivatives with tetrahedral Mg2+ are less common. Examples include salts of 2MgCl4 and adducts such as MgCl2

Answer 4

thanks but im still dont understand

Answer 5

Your answer will basically be a summary of what I just said, so your answer is:

Magnesium Chloride is an inorganic salt, which has the chemical formula of MgCl2 and molecular weight 95.210 g/mol. Predominantly magnesium chloride exists as various hydrates, particularly hexahydrate MgCl2 *6H2O having the molecular weight of 203.301 g/mol. Magnesium chloride hexahydrate occurs as a natural mineral Bischofite named after a german geologist Karl Gustav Bischo. The prefered synthetic method of preparation of anhydrous magnesium chloride is the reaction of mercury(II) chloride and magnesium: Mg + HgCl2 = MgCl2 + Hg.

Answer 6

The property:
Magnesium Chloride is a colorless crystalline compound. The salt is very hygroscopic. It has density of 2.325 g/cm3 (anhydrous), 1.56 g/cm3 (hexahydrate) and a high melting point of 987 K. Magnesium chloride hexahydrate is only stable below 373 K and decomposes at 391 K. The compound well dissolves in water with solubility of 35.5g per 100g H2O at 298 K. Dissolving MgCl2 is an exothermic process.

Answer 7

thanks do you know how the sturcture of nacl is diffrent to the structure of mgcl2

Answer 8

Sodium chloride and magnesium chloride are ionic and consist of giant ionic lattices at room temperature.
Sodium and magnesium chlorides are solids with high melting and boiling points because of the large amount of heat which is needed to break the strong ionic attractions.
Sodium and magnesium chlorides are ionic and so will undergo electrolysis when they are molten. Electricity is carried by the movement of the ions and their discharge at the electrodes.
As an approximation, the simple ionic chlorides (sodium and magnesium chloride) just dissolve in water.
Sodium chloride is a simple ionic compound consisting of a giant array of sodium and chloride ions.

A small representative bit of a sodium chloride lattice looks kind of like this:



This is normally drawn in an exploded form as something like:



The strong attractions between the positive and negative ions need a lot of heat energy to break, and so sodium chloride has high melting and boiling points.

It doesn't conduct electricity in the solid state because it hasn't any mobile electrons and the ions aren't free to move. However, when it melts it undergoes electrolysis.

Sodium chloride simply dissolves in water to give a neutral solution.



Magnesium chloride is also ionic, but with a more complicated arrangement of the ions to allow for having twice as many chloride ions as magnesium ions. This structure isn't needed for UK A level purposes.
Again, lots of heat energy is needed to overcome the attractions between the ions, and so the melting and boiling points are again high.
Solid magnesium chloride is a non-conductor of electricity because the ions aren't free to move. However, it undergoes electrolysis when the ions become free on melting.
Magnesium chloride dissolves in water to give a faintly acidic solution (pH = approximately 6).
When magnesium ions are broken off the solid lattice and go into solution, there is enough attraction between the 2+ ions and the water molecules to get co-ordinate (dative covalent) bonds formed between the magnesium ions and lone pairs on surrounding water molecules.

Hexaaquamagnesium ions are formed, [Mg(H2O)6]2+.

\[MgCl _{2[S]} + 6H _{2}O _{[I]} \rightarrow [ Mg(H _{2}O _{6}]^{2+_{[aq]}} + 2Cl _{[aq]}\]

Ions of this sort are acidic - the degree of acidity depending on how much the electrons in the water molecules are pulled towards the metal at the centre of the ion. The hydrogens are made rather more positive than they would otherwise be, and more easily pulled off by a base.
In the magnesium case, the amount of distortion is quite small, and only a small proportion of the hydrogen atoms are removed by a base - in this case, by water molecules in the solution..
The presence of the hydroxonium ions in the solution causes it to be acidic. The fact that there aren't many of them formed (the position of equilibrium lies well to the left), means that the solution is only weakly acidic.
Hydrogen ions in solution are hydroxonium ions. If you use this form, it is essential to include the state symbols.

Answer 9

I hope that made sense..

Answer 10

kind of thank you