They can cause burns to the skin, eventually reacting with and dissolving the skin. Titration is adding a measured amount of a solution of known concentration to a solution of unknown concentration to determine the unknown concentration. It is the water equilibrium constant. It is used to calculate hydronium ion or hydroxide ion concentrations. Acidic solutions have a higher concentration of hydronium ions than hydroxide ions.
Basic solutions have a higher concentration of hydroxide ions than hydronium ions.
Acidic solutions have a pH less than 7. Basic solutions have a pH greater than 7. See the equilibrium constant equation to determine why they are equal.