Mg (s) + HCl (aq) → MgCl₂(s) + H₂(g)
Looking at the equation :
We have 1 Mg at the left hand side and 1 Mg as well on the right hand side.
So that is balanced.
We have 1 H at the left hand side and 2 H on the right hand side.
So that is not balanced. Same for Chlorine. Cl.
We add 2 to the HCl on the left hand side and that balances it.
Mg(s) + 2HCl(aq) → MgCl₂(s) + H₂(g)
That would be cause part of the sodium is pure and that means it still kind of has it properties when it was an element and that its i think.
K gives 1 electron, and Br takes 1 electron.
Answer: The equation is written below.
Explanation:

According to Stoichiometry of the reaction:
2 moles of phosphate ions reacts with 1 mole of aluminum sulfate to produce 2 moles of aluminum phosphate precipitate and 3 moles of sulfate ions.
Aluminum phosphate is an odorless and white crystalline solid
The chemical equation is written above.