Final answer:
The substance that yields H+ as the only positive ion in an aqueous solution is hydrogen chloride (HCl). When HCl is dissolved in water, it completely ionizes into H+ and Cl- ions, making the solution acidic.
Step-by-step explanation:
The substance that yields H+ as the only positive ion in an aqueous solution is hydrogen chloride, HCl. When HCl dissolves in water, it ionizes completely to produce hydrogen ions (H+) and chloride ions (Cl-). According to Le Chatelier's principle, the reaction of hydrogen chloride in water can be represented as HCl (aq) → H+ (aq) + Cl⁻ (aq). This process makes the solution acidic.
Unlike hydrogen chloride, CH₃OCH₃, or dimethyl ether, does not release H+ ions when dissolved in water, as it is a neutral compound and not an acid. In contrast, strong acids like HCl substantially increase the concentration of H+ ions in the solution, and this can be related to the equilibrium constant in water, where [H+] and [OH-] equal 1.0 × 10⁻¹⁴ at room temperature. It's important to understand that all acid-base equilibria favor the side with the weaker acid and base, leading the proton to be associated with the stronger base in the case of acid reactions with water.