(bound form) used in chemistry to indicate a polymer

carbonic acid; a weak inorganic acid formed by dissolving 二氧化碳 èr​yǎng​huà​tàn in water, used in making soft drinks and chemicals

A type of organic compound formed by the reaction of an alcohol and an acid with the loss of water. Low molecular weight esters are typically fragrant liquids used as solvents or flavorings, while high molecular weight esters are solids or thick liquids found in fats and oils.