Combining a non-metal oxide with water will generally form an acid.

Here's why:

* Non-metal oxides are acidic oxides. They are formed when a non-metal combines with oxygen. Examples include:

* Carbon dioxide (CO2)

* Sulfur dioxide (SO2)

* Nitrogen dioxide (NO2)

* Water (H2O) is a neutral compound.

* When a non-metal oxide reacts with water, the oxide molecules break apart, and the non-metal combines with the hydroxide ion (OH-) from water to form an acidic compound.

Here's a simple example:

Carbon dioxide (CO2) + Water (H2O) → Carbonic acid (H2CO3)

Note: Not all non-metal oxides react with water to form acids. For example, carbon monoxide (CO) does not react with water.