Sign in
The Water Strength
Acids are molecules and ions that give protons (or H+ ions) to other substances within aqueous solutions. Some acids can dissociate completely in water while others only partially. A acid’s strength depends on how dissociated it is in aqueous solutions. It can be measured using its dissociation constant (Ksp). The hydrohalic acids include hydrochloric (HCl), and hydrofluoric (HF). As their name implies, hydrohalic acids contain both hydrogen and halide ions, and they are capable of releasing both H+ and halide ions when dissolved in water (Heller & Myers, 2019). Similarly, sulfuric acid (H2SO4) is also a strong acid, as it releases two H+ ions for every molecule of acid dissolved in water (Heller & Myers, 2019). The opposite is true for weak acids, which typically only contain H+, such as the acetic (CH3COOH), and phosphoric (H3PO4). These acids are less capable of releasing H+ ions in water, resulting in a lower dissociation constant and weaker acidity (Heller & Myers, 2019). The dissociation constant, which is the measure of the acid’s strength, can also be used to determine its water content. Some strong acids can release both H+ or halide ions. However, weak acids tend to contain H+ ions only and have a lower ability of releasing H+ in water.
