Answer:
Al(OH)₃ + 3 HCl ----> AlCl₃ + <u>3 H₂O</u>
Explanation:
In a double-displacement reaction, the cation of one compound is swapped with the cation of another. The basic structure of these reactions is:
AB + CD ----> AD + CB
In this reaction, the aluminum (Al) of Al(OH₃) is replaced by the hydrogen (H) of HCl, and vice versa.
The first resulting compound is AlCl₃. The chlorine has a subscript of 3 in order to eliminate the +3 charge from the Al cation (+3 + 3(-1) = 0). The second resulting compound is HOH, most commonly written as H₂O. There needs to be a coefficient of 3 in front of H₂O to balance the equation.
The complete balanced equation is:
Al(OH)₃ + 3 HCl ----> AlCl₃ + <u>3 H₂O</u>
