If zinc is put in hydrofluoric acid, it will react vigorously to form zinc fluoride and hydrogen gas. The reaction is as follows:

Zn + 2HF -> ZnF2 + H2

The reaction is highly exothermic, meaning that it releases a lot of heat. The hydrogen gas produced is flammable and can pose a safety hazard. Therefore, it is important to handle zinc and hydrofluoric acid with care and to follow proper safety precautions when working with these substances.