[kpcsmcri]

Please help me by answering this.

[woelen]

I'm afraid you can't. Many hydrated metal salts, when heated, do not only loose water, but also acid. So, in your case you may end up with HCl fumes, water vapor and MgO as a residue.

I'm not sure about MgCl2.6H2O, but I know a similar thing happens with MANY hydrated metal salts, e.g. FeCl3.6H2O, Mg(NO3)2.6H2O, AlCl3.6H2O, Cu(NO3)2.3H2O. They all loose acid on heating, leaving a basic metal salt at best or being completely decomposed to the oxide/hydroxide.

[science2000]

But couldn't anhydrous H2SO4 "pull" the water molecules safely out of hydrated magnesium chloride? I've seen it added to sugar, and it pulls the water out of it leaving behind carbon. it's a powerful dehydrating agent.

[AWK]

You can obtain anhydrous crystals of {Mg(NH3)6]Cl2. They loss ammonia during warming. This method is patented

[woelen]

But couldn't anhydrous H2SO4 "pull" the water molecules safely out of hydrated magnesium chloride? I've seen it added to sugar, and it pulls the water out of it leaving behind carbon. it's a powerful dehydrating agent.

This won't work, you also loose your chloride and impure MgSO4 is left behind. Gaseous HCl will escape. The same thing happens when NaCl is added to H2SO4.