Final answer:
True, water is amphoteric and can act as either an acid or a base. This dual behavior is due to its ability to donate or accept protons, illustrated in its reactions with stronger acids or bases, and in water's self-ionization.
Step-by-step explanation:
The statement that water can be an acid or a base depending on the situation is true. According to the Brønsted-Lowry theory, an acid is a proton (H+) donor and a base is a proton acceptor. When water acts as a base, it can accept a proton from a stronger acid. For instance, in the reaction with hydrochloric acid (HCl), water accepts a proton from HCl, forming hydronium ions (H3O+). Conversely, water can donate a proton to a stronger base, such as ammonia (NH3), where it acts as an acid. This demonstrates that water is amphoteric, meaning it can behave as either an acid or a base depending on the reactants it encounters. This dual ability comes from water's capacity to donate or accept protons, which is illustrated in the self-ionization of water, where one water molecule donates a proton to another, forming both hydronium ions and hydroxide ions (OH-).