Acid-Base Reactions and Buffers Practice Test

The added $\mathrm{H^+}$ is primarily consumed by $\mathrm{C_2H_3O_2^-}$ to form $\mathrm{HC_2H_3O_2}$, so the pH decreases only slightly.

The added $\mathrm{H^+}$ causes $\mathrm{HC_2H_3O_2}$ to dissociate completely, making the solution behave like a strong acid.

The added $\mathrm{H^+}$ is primarily consumed by $\mathrm{HC_2H_3O_2}$ to form $\mathrm{C_2H_3O_2^-}$, so the pH remains exactly constant.

The added $\mathrm{H^+}$ remains mostly as free $\mathrm{H^+}$ because buffers neutralize only added base, so the pH decreases sharply.

The added $\mathrm{H^+}$ reacts mainly with $\mathrm{Na^+}$ ions, preventing any change in pH.