Final answer:
When aluminum phosphate reacts with magnesium chloride in aqueous solution, no chemical reaction occurs because both reactants are comprised of cations and do not typically displace one another, which would simply result in the original reactants without forming new products.
Step-by-step explanation:
The reaction between aluminum phosphate (AlPO4) and magnesium chloride (MgCl2) in an aqueous solution is a double displacement reaction. However, since both magnesium ions (Mg2+) and aluminum ions (Al3+) are cations, they will not typically replace each other in a compound. Generally, a cation would replace another cation if it is more reactive according to the activity series, but this principle applies primarily to single displacement reactions.
For a double displacement reaction, it involves two ionic compounds where the cations and anions essentially 'swap' partners. The proper approach is to identify the possible products and then determine if they are soluble in water or form a precipitate based on solubility rules. In this particular case, no reaction occurs because the most likely products (if any) would be the exchange of cations, which simply regenerate the original reactants due to their solubility in water. If anything, we would just remain with the original reactants: AlPO4 and MgCl2. Therefore, there is no reaction and a balanced equation cannot be provided for this scenario.