Carbon dioxide (CO2) has a molecular formula of CO2 and a relative molecular mass of 44.01. It is a colorless, odorless, tasteless, and non-toxic gas. Its melting point is -56.6°C (at 526.89 kPa), and its boiling point is -78.6°C (at which it sublimes); its density is 1.977 g/L. It is soluble in water, with a solubility of 0.1449 g per 100 g of water at 25°C; its aqueous solution is acidic. At 20°C, carbon dioxide can be liquefied by applying a pressure of 5978.175 kPa, at which point it has a relative density of 1.0310. When liquid carbon dioxide is cooled to -23.1°C under a pressure of 415 kPa, it forms a solid. Solid carbon dioxide, also known as "dry ice," absorbs heat and sublimes directly into a gas. It is also soluble in ethanol, with a solubility of 23.23 mL per 100 mL.
Consuming carbonated beverages allows body heat to be expelled along with the carbon dioxide gas, thereby creating a cool and refreshing sensation while also stimulating the palate. Furthermore, the reduction in pH value provides a preservative effect.
