Classify each species as either a Bransted-Lowry acid, Brensted-Lowry base, or as amphiprotic. Select the single best answer for each part.

H2CO3?

H2PO^-_4?

PO^3-_4?

1 answer

Let's classify each species based on the Brønsted-Lowry acid-base theory.

  1. H2CO3 (Carbonic acid): This compound can donate a proton (H⁺) and acts as an acid. Therefore, it is classified as a Brønsted-Lowry acid.

  2. H2PO4⁻ (Dihydrogen phosphate ion): This species can both donate a proton (acting as an acid) and accept a proton (acting as a base). Therefore, it is classified as amphiprotic.

  3. PO4^3- (Phosphate ion): This species can accept a proton to form HPO4^2-, but does not donate a proton. Therefore, it acts only as a base in this context and is classified as a Brønsted-Lowry base.

To summarize:

  • H2CO3: Brønsted-Lowry acid
  • H2PO4⁻: Amphiprotic
  • PO4^3-: Brønsted-Lowry base