Question

According to the Bronsted-Lowry theory, which of the following would you expect to act as an acid? Which as a base? (a) \(\mathrm{CH}_{3} \mathrm{O}^{-}\) (b) \(\mathrm{CO}_{3}^{2-}\) (c) \(\mathrm{HAsO}_{4}^{2-}\)

Short answer

Question: According to the Bronsted-Lowry theory, identify whether the following substances can act as acids or bases: (a) \(\mathrm{CH}_{3} \mathrm{O}^{-}\) (b) \(\mathrm{CO}_{3}^{2-}\) (c) \(\mathrm{HAsO}_{4}^{2-}\) Answer: (a) Acid, (b) Base, (c) Both acid and base

Step-by-step solution

Identify proton donors and acceptors for each molecule

(a) For \(\mathrm{CH}_{3} \mathrm{O}^{-}\), it already has an extra electron which indicates that it has accepted a hydrogen ion (H+). The structure can donate a proton back, therefore acting as an acid. (b) For \(\mathrm{CO}_{3}^{2-}\), it has two negative charges, meaning it can accept up to two protons (H+). As a result, it can act as a base. (c) For \(\mathrm{HAsO}_{4}^{2-}\), it has one proton (H+) and two negative charges. It can both donate the proton, acting as an acid, and accept a proton to balance the charges, thereby acting as a base.

Summarize the result

So, according to the Bronsted-Lowry theory: (a) \(\mathrm{CH}_{3} \mathrm{O}^{-}\) can act as an acid. (b) \(\mathrm{CO}_{3}^{2-}\) can act as a base. (c) \(\mathrm{HAsO}_{4}^{2-}\) can act as both an acid and a base.