When solutions of aluminum chloride (AlCl3) and sodium hydroxide (NaOH) are mixed, a chemical reaction takes place, resulting in the formation of aluminum hydroxide (Al(OH)3) and sodium chloride (NaCl). The reaction can be represented by the following chemical equation:

AlCl3 (aq) + 3NaOH (aq) → Al(OH)3 (s) + 3NaCl (aq)

In this reaction, the aluminum ions (Al3+) from aluminum chloride react with the hydroxide ions (OH-) from sodium hydroxide to form aluminum hydroxide, which is an insoluble compound and precipitates as a solid. Sodium chloride remains in the solution as it is soluble in water.

The reaction between aluminum chloride and sodium hydroxide is an example of a precipitation reaction, which occurs when two solutions containing soluble ionic compounds are mixed, resulting in the formation of an insoluble compound that precipitates out of the solution.