HCl and Hydrochloric Acid are two different things. HCl is Hydrogen Chloride, and it is a gas at room temperature. Hydrochloric Acid is the result of Hydrogen Chloride dissolved in water.
The formula for Hydrochloric Acid and Hydrogen Chloride is the same. Context strongly implies U2 meant Hydrochloric Acid as it is liquid at room temperature. It doesn't really matter because Hydrogen Chloride can be a liquid below 188K anyway
