Hydrogen and chlorine react to form hydrogen chloride (HCl), a colorless gas with a pungent, acidic odor.

Here's the chemical equation for the reaction:

H₂ + Cl₂ → 2 HCl

Hydrogen chloride is highly soluble in water, and when dissolved, it forms hydrochloric acid (HCl), a strong acid.

Here are some important points to remember:

* This reaction is highly exothermic, meaning it releases a lot of heat.

* Hydrogen chloride gas is toxic and corrosive, so it's important to handle it with care.

* Hydrochloric acid is a common industrial chemical used in various applications, including metal cleaning, leather processing, and food production.