Final answer:
The Brønsted-Lowry theory defines acids as proton donors and bases as proton acceptors. By identifying these in a reaction, one can label the corresponding conjugate base and conjugate acid. An example of a non-proton Lewis acid-base reaction is the interaction between BF₃ and NH₃.
Step-by-step explanation:
The subject of this question pertains to the Brønsted-Lowry theory of acids and bases in chemistry. The Brønsted-Lowry definition considers an acid as a proton donor and a base as a proton acceptor. To answer the student's question, firstly, we have to identify the Brønsted-Lowry acid, its conjugate base, the Brønsted-Lowry base, and its conjugate acid within the provided reaction equations.
For example, in the chemical reaction H₂O (acid) + NH₃ (base) → OH⁻ (conjugate base) + NH₄⁺ (conjugate acid), water (H₂O) donates a proton to ammonia (NH₃), forming hydroxide ion (OH⁻) and ammonium ion (NH₄⁺). Thus, water is acting as the Brønsted-Lowry acid and ammonia as the Brønsted-Lowry base. The hydroxide ion is the conjugate base of water, and the ammonium ion is the conjugate acid of ammonia.
Additionally, we can regard this reaction as an electron-pair transfer process, where the ammonia molecule donates an electron pair to form a bond with the proton from water.
An example of a Lewis acid-base reaction that does not involve protons might be the reaction between boron trifluoride (BF₃), a Lewis acid, and ammonia (NH₃), a Lewis base, where the nitrogen atom in ammonia donates an electron pair to the boron atom in boron trifluoride.
The direction of the acid-base equilibrium is often dictated by the relative strengths of the acids and bases involved. A stronger acid and stronger base will generally react to form a weaker acid and weaker base.
For Exercise 7.2.1, the Brønsted-Lowry acid is dihydrogen phosphate ion (H₂PO₄⁻), and the Brønsted-Lowry base is the water molecule (H₂O).