What is the reaction between copper nitrate and potassium hydroxide?

They will combine to form copper(II) hydroxide, an insoluble liquid that precipitates out of the solution. The other product will be aqueous potassium nitrate, which, as its name suggests, will exist as ions in the aqueous solution.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

answer; 4 electrons;