carbon dioxide is moderately soluble in cold water but is completely boiled out if the water is boiled.Solubility increases rapidly with pressure. How is the above phenomenon used in the production of aerated drinks?
Soft drinks are pressurized (to make gas more soluble) and cooled (to make gas more soluble). If you pop the top of a cola and leave it open to the air it will go flat in a short time since all of the dissolved CO2 will be gone.
The phenomenon you described is indeed utilized in the production of aerated drinks. Let me explain how:
1. Carbonation process: Aerated drinks, such as carbonated soft drinks or soda, contain dissolved carbon dioxide gas, which creates the fizz and refreshing bubbles. To achieve this, cold water is used as a solvent.
2. Solubility in cold water: Carbon dioxide (CO2) is moderately soluble in cold water, meaning it can dissolve to some extent. When water is cold, it has a higher capability to hold dissolved gases.
3. Pressurization: The carbonation process involves pressurizing the container (e.g., a bottle or can) containing the drink. This increased pressure helps enhance the solubility of carbon dioxide in water.
4. Carbonation under pressure: The cold water is mixed with carbon dioxide gas under high pressure. As a result, a substantial amount of CO2 gets dissolved in the water, creating a carbonated beverage.
5. Seal and stability: The container is then sealed to maintain the pressure and prevent the escape of the dissolved carbon dioxide. This is why you often hear a "pop" when opening a carbonated drink – it is the sound of the pressure being released.
6. Boiling out: When the container is opened, the internal pressure decreases, and the solubility of carbon dioxide in water decreases as well. So, if you were to boil the water, as you mentioned, the dissolved carbon dioxide would escape, leaving the water without any fizz or bubbles.
In summary, the carbonation process in the production of aerated drinks takes advantage of the moderate solubility of carbon dioxide in cold water and the increased solubility under pressure. By controlling the pressure and temperature, carbonated beverages are created, which provide the effervescent experience that we enjoy.