大象传媒

The presenter and a diver discuss how an acid-plus-base reaction helps divers. The divers use a 'rebreather' in which soda lime, a strong alkali, is used to neutralise the acidic carbon dioxide which they exhale. The divers then re-breathe any recovered oxygen and water vapour, a waste product produced in the reaction that helps prevent dehydration. This system lasts three times as long as conventional gas bottles and creates very few bubbles, which is good for underwater filming.