Hydrochloric acid or HCl is classified as a strong acid which means it dissociates into ions completely when in water. It ionizes into hydrogen ions and chloride ions. pH
is a scale which measures the acidity or alkalinity of a solution. It is expressed as the negative logarithm of the
concentration of hydronium ions or the hydrogen ions. To determine pH, we need to determine the concentration of the hydrogen ions. We do as follows:
moles H+ = 1.0 M HCl ( 0.00005 L ) ( 1 mol H+ / 1 mol HCl ) = 0.00005 mol H+
Concentration of H+ = 0.00005 mol H+ / 1.0 L = 0.00005 M
pH = -log [H+]
pH = -log [0.00005]
pH = 4.3
