A neat experiment you can do at home with off-the-shelf Muriatic acid. Muriatic acid contains Hydrochloric acid, which reacts with the zinc insid A neat experiment you can do at home with off-the-shelf Muriatic acid. Muriatic acid contains Hydrochloric acid, which reacts with the zinc inside a modern penny. After the acid eats away all the zinc, all that`s left is a copper shell only one thousandth of an inch thick! You can use this penny shell for an old but simple magic trick where you hide a dime inside it. more >> <<less