Final answer:
The reaction described is a double displacement reaction, where the cations and anions from the original compounds exchange to form new compounds, sodium hydroxide, and potassium phosphate.
Step-by-step explanation:
The reaction between sodium phosphate and potassium hydroxide to form sodium hydroxide and potassium phosphate is an example of a double displacement reaction, also known as a metathesis reaction. In this reaction type, the cations and anions of the reacting molecules switch places, forming new compounds. It's important to note that sodium phosphate can exist as either sodium dihydrogen phosphate (NaH2PO4) or sodium monohydrogen phosphate (Na2HPO4), both of which interact in various ways with strong bases and acids.
During a typical double displacement reaction, compounds swap components, much like the example given with aqueous solutions of copper (II) chloride and potassium phosphate where a precipitate of copper (II) phosphate is formed. Similarly, when a weak base like Na2HPO4 comes in contact with a strong alkali such as NaOH, water can be produced as a byproduct as the base reverts back to its weak form.