Here's why:

* Zwitterions are molecules that have both a positive and negative charge within the same molecule. This is typically achieved by the presence of both acidic and basic groups within the molecule, which can donate and accept protons, respectively.

* Ammonium acetate is a salt formed from the reaction of ammonia (NH3) and acetic acid (CH3COOH). The ammonium ion (NH4+) has a positive charge, while the acetate ion (CH3COO-) has a negative charge.

* The positive and negative charges in ammonium acetate are not located on the same molecule. They are on separate ions, the ammonium ion and the acetate ion.

Therefore, ammonium acetate is not a zwitterion, but rather a simple ionic compound.