In today's activity we performed a single replacement chemical reaction. We mixed Zinc (Zn) with Hydrochloric acid (HCl) in side a 1,000ml Erlenmyer flask. When the reaction began, we put a balloon over the top of the flask to capture the gas. Some metals react with acids to produce hydrogen. The metal changes place with the hydrogen in the acid. The hydrogen is set free. Zinc is a metal that will react with Hydrochloric acid. This reaction produces. Zinc chloride (ZnCl2) and Hydrogen.