b) Limitations of Acid-Base Theories:

Here are the answers to the questions: b) Limitations of Acid-Base Theories: i) Arrhenius theory: This theory is limited to reactions occurring in aqueous solutions* and cannot explain acid-base behavior in non-aqueous solvents or reactions that do not involve the formation of H^+ or OH^- ions. For example, it cannot explain why ammonia (NH_3) is a base, as it does not contain OH^-. ii) Brønsted-Lowry theory: This theory requires the transfer of a proton* (H^+) for a reaction to be classified as acid-base. It cannot explain reactions where no proton transfer occurs, such as the reaction between boron trifluoride (BF_3) and ammonia (NH_3), which is an acid-base reaction according to the Lewis theory. iii) Lewis theory: While the broadest theory, it can be more complex to apply and does not easily predict the relative strengths* of acids and bases quantitatively. The concept of electron pair donation/acceptance can also be less intuitive for some reactions compared to proton transfer. 2. Amphiprotic Species: An amphiprotic species is a molecule or ion that can act as both a Brønsted-Lowry acid (by donating a proton) and a Brønsted-Lowry base (by accepting a proton). Illustration with equations: Water (H_2O) is a common example of an amphiprotic species. When acting as an acid (donating a proton to a base like ammonia): H_2O(l) + NH_3(aq) OH^-(aq) + NH_4^+(aq) When acting as a base (accepting a proton from an acid like hydrochloric acid): H_2O(l) + HCl(aq) H_3O^+(aq) + Cl^-(aq) 3. Neutralization Reaction and Conjugate Acid-Base Pairs: The neutralization reaction between hydrochloric acid (HCl) and magnesium hydroxide (Mg(OH)_2) is: 2HCl(aq) + Mg(OH)_2(s) → MgCl_2(aq) + 2H_2O(l) The conjugate acid-base pairs are: HCl (acid) and Cl^- (conjugate base) H_2O (acid, formed from Mg(OH)_2) and OH^- (base, from Mg(OH)_2) 3 done, 2 left today. You're making progress.