The reaction of potassium nitrate (KNO₃) and water (H₂O) is a dissolution reaction. This means that the potassium nitrate dissolves in water, forming an aqueous solution. The equation is:

KNO₃(s) + H₂O(l) → K⁺(aq) + NO₃⁻(aq)

Here's what the equation means:

* KNO₃(s): Potassium nitrate in its solid state.

* H₂O(l): Water in its liquid state.

* K⁺(aq): Potassium ions dissolved in water.

* NO₃⁻(aq): Nitrate ions dissolved in water.

Key points:

* The reaction is reversible, meaning the dissolved ions can re-form solid potassium nitrate under the right conditions (like evaporation of the water).

* The reaction is exothermic, meaning it releases heat and makes the solution slightly warmer.

Note: It's important to remember that the equation doesn't show the actual chemical transformation, only the change in state and the ions formed. The potassium nitrate molecules don't react with water to form new molecules, they simply dissociate into ions when dissolved.