When we open the bottle of soda we always notice the fizz. This is because during the soda manufacturing large number of molecules of carbon dioxide gas are forced into the bottle and are dissolved at a pressure up to 1200 pounds per square inch in the water than it would be in the normal atmospheric conditions. This gas gets dissolve in the water and forms carbonic acid because of which it has tangy taste. The main aim is to force more and more molecules of carbon dioxide gas in the soda. The solution remains flat in the bottle until it is disturbed this is because carbon dioxide molecules does not separate from water and they are under liquidâ€™s surface tension. Now when we open the bottle we release that pressure. It gains the energy to separate gas molecules and water. The room temperature enters into the bottle and the drink starts getting warmer quickly. Carbon dioxide also gets warmer and starts rising towards the surface in the form of bubbles because it has gained kinetic energy. After reaching the surface these bubbles pop.
Always a gas when dissolved in water separates itself from the solution explosively if it is suddenly disturbed. When we shake the bottle lots of small bubbles are created and the dissolved carbon dioxide joins these bubbles to vaporize quickly which results in more fizz.
Ice cubes added to the soda releases the dissolved gas into the soda which causes continuous fizz. One way to keep soda from getting flat easily is not to shake it and other is to cap the bottle tightly so that the room temperature cannot easily enter into the bottle and the liquid remains cool.