please help answer 1;2;3 for Fischer Esterification

F. Given that the alcohol was used in excess, there was certainly a good deal of it present when the reaction mixture reached equilibrium. What evidence did you have of the presence of unreacted carboxylic acid during the first week or after storage of the mixture for a week? The reaction mixture was extracted with aqueous sodium bicarbonate. Show below using STRUCTURAL REPRESENTATIONS the CURLY-ARROW MECHANISM of reaction of carboxylic acid with the bicarbonate ion to produce carboxylate and carbonic acid. Show STRUCTURAL REPRESENTATIONS for the decomposition of the carbonic acid into carbon dioxide and water. You need NOT show a mechanism. (It is a complex, multistep mechanism