To determine which compound has the largest Van't Hoff factor (i), we need to analyze how each compound dissociates in solution. The Van't Hoff factor represents the number of particles into which a compound dissociates in solution.

Starting with aluminum chloride (AlCl₃), this ionic compound dissociates into one aluminum ion (Al³⁺) and three chloride ions (Cl^-), resulting in a total of four ions. Therefore, the Van't Hoff factor (i) for aluminum chloride is 4.

Next, we consider a covalent compound, which consists solely of nonmetals. Such compounds do not dissociate into ions, so their Van't Hoff factor is 1.

For zinc oxide (ZnO), which is an ionic compound, it dissociates into one zinc ion (Zn²⁺) and one oxide ion (O^2-), giving a total of two ions. Thus, the Van't Hoff factor for zinc oxide is 2.

Ammonia (NH₃) is also a covalent compound and does not dissociate into ions, resulting in a Van't Hoff factor of 1. Similarly, phosphorus pentasulfide (P₂S₅) is a covalent compound with a Van't Hoff factor of 1.

In summary, the compound with the highest Van't Hoff factor is aluminum chloride (AlCl₃), with a value of 4, indicating it produces the most particles in solution compared to the other compounds analyzed.