Final answer:
1)nH₂SO₄ (sulfuric acid) is an Arrhenius acid as it dissociates in water to release H⁺ ions, identifying it as a strong acid. The other compounds are either neutral salts or bases.
Step-by-step explanation:
The compound that is an Arrhenius acid among the given options is H₂SO₄ (sulfuric acid). An Arrhenius acid is a compound that increases the concentration of H⁺ ions when dissolved in water.
Sulfuric acid dissociates in water to release H⁺ ions, making it a strong acid. KCl (potassium chloride) is a neutral salt and not an acid.
NaOH (sodium hydroxide) is an Arrhenius base as it increases the OH⁻ ion concentration in aqueous solution.
Lastly, NH₃ (ammonia) is not an Arrhenius acid; it is actually a weak base according to the Brønsted-Lowry theory but does not increase OH⁻ ion concentration in an aqueous solution.
An Arrhenius acid is a compound that dissociates to yield hydrogen ions (H+) in aqueous solution.
Examples of Arrhenius acids include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and nitric acid (HNO₃). Based on this definition, the correct answer to your question is (1) H₂SO₄ since it dissociates to yield H+ ions in solution.