* HCl is a strong acid: HCl readily dissociates in water, meaning it breaks apart into hydrogen ions (H+) and chloride ions (Cl-).
* Hydrogen ions determine pH: The pH scale measures the concentration of hydrogen ions in a solution. A lower pH indicates a higher concentration of H+ ions, making the solution more acidic.
* Increased acidity: As HCl dissolves in water, it releases H+ ions, increasing their concentration in the water. This increase in H+ ions leads to a decrease in pH, making the solution more acidic.
In summary: Adding gaseous HCl to water increases the concentration of hydrogen ions (H+), lowering the pH and making the solution more acidic.
