The layers in a particular gumball are (1) an outer layer of citric acid and malonic acid; (2) a layer of sugar and flavoring; (3) a layer of sodium bicarbonate (NaHCO₃); and (4) gum.When a person starts to eat one of these gumballs, s/he puckers, smiles, and then foams at the mouth before starting to chew the gum itself.Where did the foam come from?

Question

Quizplus · Accepted Answer

The foam comes from the reaction between the acids (citric acid and malonic acid) and sodium bicarbonate, which produces carbon dioxide gas. This reaction forms unstable carbonic acid which quickly decomposes into water and carbon dioxide gas, causing the foaming effect.

The Layers in a Particular Gumball Are (1) an Outer