Final answer:
The assertion that weak acids and bases are highly reversible, requiring an equilibrium arrow, is true. Their reactions are characterized by a dynamic chemical equilibrium, with the equilibrium favoring the weaker acid and base.
Step-by-step explanation:
The statement that weak acids and bases are highly reversible, and this requires an equilibrium arrow, is A) True. Weak acids and bases only partially dissociate in water and their reactions are characterised by a state of dynamic chemical equilibrium. For example, if we consider the ionization of acetic acid (HC₂H₃O₂), the equation is often written as:
HC₂H₃O₂ (aq) + H₂O (l) ⇌ H₃O⁺ (aq) + C₂H₃O₂⁺ (aq)
The double arrows (⇌) indicate that the reaction can proceed in both the forward and reverse directions, which means that at equilibrium, both the reactants and products are present in the solution. Furthermore, acid-base equilibrium tends to favor the formation of the weaker acid and base. Hence, in a reaction between a stronger acid and a stronger base, the equilibrium will shift towards the side with the weaker acid and weaker base, as representatively indicated by a longer equilibrium arrow pointing in that direction.