Question

Which is the correct formula for the compound made when aqueous solutions containing a dissolved magnesium compound and a dissolved chloride compound are mixed?

Answer 1

it would be MgCl₂ ~ Magnesium Chloride. 

Answer 2

Answer:

The correct formula for the compound made when aqueous solutions containing a dissolved Magnesium and Chloride are mixed is Magnesium chloride $MgCl_2$

Explanation:

If we suppose the existence of two components in aqueous solutions containing Magnesium and Chloride. For example: Hydrochloric acid - HCl and Magnesium hydroxide - $Mg(OH)_2$.

The global reaction would be:  

HCl + $Mg(OH)_2$ --> $MgCl_2$ + $H_2 O$

It means, Hydrochloric acid is neutralized with Magnesium hydroxide to produce Magnesium chloride and Water.  

Besides of that, we can analyze the aqueos solution of every componenent:

For Hydrochloric acid:

HCl + $H_2 O$ --> $H_3O^+$ + $Cl^-$

For Magnesium hydroxide

$Mg(OH)_2$ +  $H_2 O$ --> $H_2O-(OH)^-$ + $Mg^+2$

Finally, the ionic compounds will form the salt:

$Mg^+2$ + $Cl^-$ ->  $MgCl_2$