Which of the following phenomena occurs, when a small amount of acid is added to water?

When a small amount of acid is added to water, both ionization and dilution occur. Ionization involves the dissociation of the acid into hydrogen ions (H+) and conjugate base ions in water, making the solution acidic. Dilution refers to the process where the addition of acid to water results in a decrease in the concentration of the acid, spreading it out in a larger volume of water.