Acids are substances that donate protons (H+) in a chemical reaction. The strength of an acid is determined by its ability to donate protons. The higher the concentration of H+ ions in a solution, the stronger the acid.
Out of the given options, HCl is the strongest acid because it completely dissociates in water, releasing a large number of H+ ions. The dissociation of HCl can be represented as follows:
HCl → H+ + Cl-
The other compounds, NH3 (ammonia), NaOH (sodium hydroxide), and H2CO3 (carbonic acid), are not as strong acids as HCl. NH3 is a weak base, NaOH is a strong base, and H2CO3 is a weak acid.
