American Chemical Society (ACS) Chemistry Practice Exam

When hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the result is the formation of sodium chloride (NaCl) and water (H₂O). This reaction is a classic example of an acid-base neutralization, where the acid donates a proton (H⁺) and the base donates a hydroxide ion (OH⁻). When these ions combine, they form water. The remaining ions, Na⁺ from sodium hydroxide and Cl⁻ from hydrochloric acid, combine to form sodium chloride, which is common table salt. This reaction can be summarized by the overall balanced chemical equation: HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l) In this process, the characteristics of both the acid and the base are neutralized, leading to a solution that is not acidic or basic. Understanding this fundamental reaction is essential in chemistry, particularly in titration experiments and various applications in laboratory settings.