One phase change we would see in a root beer float is the change from liquid to gas.
Explanation:
In root beer float we can see all three states: solid, liquid and gas.Solid being the ice cream,beer as the liquid and the reaction after mixing the creates the gas.
As we mix ice cream (solid) and beer (liquid) in a glass then the bubble formation process occurs which is called as carbonation creating the gas.
Hence root beer float is a simple experiment showing all three states and change in phase from solid and liquid into gas.
