When a non-metallic oxide is mixed with water, it typically produces an acid.

Here's why:

* Non-metallic oxides are compounds formed between a non-metal and oxygen. These oxides are often referred to as acidic oxides.

* When these oxides react with water, they form oxoacids. Oxoacids are acids that contain oxygen in their structure.

Here are some examples:

* Carbon dioxide (CO2) + water (H2O) → carbonic acid (H2CO3)

* Sulfur dioxide (SO2) + water (H2O) → sulfurous acid (H2SO3)

* Nitrogen dioxide (NO2) + water (H2O) → nitric acid (HNO3)

Note:

* Not all non-metallic oxides react with water to form acids. Some, like carbon monoxide (CO), are relatively unreactive with water.

* The strength of the acid produced depends on the non-metallic oxide. For example, sulfur dioxide produces a weak acid (sulfurous acid), while nitrogen dioxide produces a strong acid (nitric acid).