The model presents various types of carboxylic acids - simple carboxylic acids, dicarboxylic acids and aromatic carboxylic acids. The first group of acids consists of the compounds formed by linkage of either hydrogen or alkyl (unsaturated) residues to the group COOH. Dicarboxylic acids contain two COOH groups. Aromatic acids in addition to one or several COOH groups include benzene ring. To observe examples of these compounds in the model you should switch into an appropriate regime by pressing of any of two radio-buttons below the main window. Each regime determines which of the above-mentioned group of carboxylic acids would be demonstrated. Then, to see the next example of the group press the "Next" button. The "Reset" button returns the model into initial state.