The solubility of carbon dioxide increases with partial pressure. Partial pressure refers to the pressure exerted by a gas if it occupies a volume alone. The solubility of carbon dioxide is proportional to its partial pressure. When carbon dioxide molecules strike the surface of a solvent, they produce a corresponding amount of pressure. The volume of carbon dioxide that dissolves in a liquid substance is directly proportional to the pressure.
Carbon dioxide becomes less soluble as temperature increases and vice versa. This is because carbon dioxide is a gas; gas molecules have low affinity for each other. Carbon dioxide molecules form weak bonds with the solvent molecules when it dissolves. The strength of these bonds increases in proportion to falling temperature, resulting in higher solubility of carbon dioxide.
Carbon dioxide molecules are non-polar molecules. This non-polar characteristic occurs when polarization happens between two oxygen molecules and one carbon molecule in a carbon dioxide molecule toward the more electronegative oxygen molecules. This means that carbon dioxide can only dissolve in solvents that are non-polar like it. Thus the solubility of carbon dioxide in solvents with polar molecules such as water is very low.
PH is the acidity or alkalinity value in a solution. A pH scale ranges from 1 to 14. A scale of 7 is neutral while a pH scale of less than 7 is acidic, and a scale of more than 7 is basic. Solubility of carbon dioxide is low at a pH value of 1 to 5. However, at a pH value of 6 and above, solubility of carbon dioxide increases steadily.