Why does cola fizzes more when poured on a new cup than poured on a cup that previously had cola on it?

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Why does cola fizzes more when poured on a new cup than poured on a cup that previously had cola on it?

In: Chemistry
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Bubbles form faster on rough, dry surfaces. Drop a grain of sand into a carbonated drink and you will see bubbles rising up from it. What happens is that it is easier for a bubble to grow larger than it is for a bubble to “start”. These rough surfaces contain a fair amount of trapped air in the cracks. That trapped air becomes a place for bubbles to grow and break off. These are called “nucleation sites”.

A new cup is going to have a fair amount of these dry rough places. Imperfections in the glass, etc. A used cup will still have these but it will also be coated with a thin film of liquid. There will still be places for bubbles to grow, but perhaps not as many.

Also temperature, if you pour a relatively cooler carbonated drink in a room temperature cup, the gas will heat and expand and more fizz would result when compared to a cup that has acclimated to the drink’s cooler temp