Label each reactant as either a Bronsted-Lowry acid or a Bronsted-Lowry base.

a. HF (aq) + H2O (l) - -> H3O + (aq) + F - (aq)

HF (aq) ["Bronsted-Lowry acid", "Bronsted-Lowry base"]

H2O (l) ["Bronsted-Lowry acid", "Bronsted-Lowry base"]

b. HCO3 - (aq) + H2O (l) - -> H2CO3 (aq) + OH - (aq)

HCO3 - (aq) ["Bronsted-Lowry base", "Bronsted-Lowry acid"]

H2O (l) ["Bronsted-Lowry acid", "Bronsted-Lowry base"]

a. HF (aq) ["Bronsted-Lowry acid"]

H₂O (l) ["Bronsted-Lowry base"]

b. HCO₃⁻ (aq) ["Bronsted-Lowry base"]

H₂O (l) ["Bronsted-Lowry acid"]

Explanation:

Bronsted Lowry theory expose this:

Acid is the one that release a proton

Base is the one that accept a proton

a. HF (aq) + H₂O (l) → H₃O⁺ (aq) + F⁻ (aq)

HF is the acid, it donates the proton to water.

Water is the base, it accepts the H⁺

b. HCO₃⁻ (aq) + H₂O (l) → H₂CO₃ (aq) + OH⁻ (aq)

Anion bicarbonate is the base because it accepted the H⁺ from the water, which is the acid.