Final answer:
CH₃NH₂, also known as methylamine, is the compound NOT regarded as an Arrhenius acid because it does not produce H+ ions in aqueous solution but instead produces OH- ions, making it an Arrhenius base.
Step-by-step explanation:
The student asked which of the following compounds is NOT an Arrhenius acid: A) H₂SO₄ B) CH₃CO₂H C) HNO₃ D) CH₃NH₂. An Arrhenius acid is defined as a compound that produces H+ ions when dissolved in water. Compounds A), H₂SO₄, B), CH₃CO₂H, and C), HNO₃, all release H+ ions in aqueous solutions and are thus Arrhenius acids. However, compound D), CH₃NH₂, which is methylamine, does not produce H+ ions but instead produces OH- ions when reacting with water. Therefore, CH₃NH₂ is an Arrhenius base, not an acid.