Heat the crucible. Make sure that there is good ventilation, because an acrid gas will be released in the reaction. To make an iodine gas tube place a few iodine crystals into a flask and seal it with a stopper. Gently heat the flask for about 10 seconds. The crystals will sublimate and a purplish gas will be visible in the flask.
Iodine gas is poisonous.
Add about 5 mL of dilute hydrochloric acid. Cover the test tube to prevent the gas from escaping. Hydrogen gas was produced in the reaction between the zinc and hydrochloric acid. This gas is highly flammable and gives off a characteristic small explosion, when ignited in a test tube. Activity 6 Take a shoe box and make cuts in the box to make flaps which can be opened.