The beginning of the animation portrays a solution of silver nitrate and sodium chloride. Notice that the solution consists of silver ions, nitrate ions, sodium ions, and chloride ions. As equilibrium is attained, silver chloride precipitates because of its low solubility, while sodium ions and nitrate ions are left in solution.
Hydronium ion, produced by the reaction of an acid such as hydrochloric acid with water, transfers a hydrogen ion to the carbonate to form the hydrogen carbonate ion. The hydrogen carbonate then accepts a second hydrogen to form carbonic acid. Most of the carbonic acid molecules then decompose to carbon dioxide and water. Because carbon dioxide is a gas and has a limited solubility in water, most of it bubbles out of the solution.
In the first frames of this animation the equilibrium between solid calcium fluoride and the ions in solution is shown. Then hydrogen chloride molecules are added. These molecules release hydrogen ions to the water molecules and, as is shown here, to the fluoride ions. Because hydrogen fluoride is a weak electrolyte, this ion-combination reaction proceeds to the right and, consequently, the calcium fluoride dissolves. The products of the reaction are hydrogen fluoride and calcium chloride (which is soluble).