A 50:50 mixture of a pair of enantiomers. A racemic solution is obtained when two achiral agents react to form a chiral product. Such a solution is optically inactive, as the rotations of the two enantiomers cancel each other out. It can be purified into only one 'side' enantiomer in a process known as resolution, by coverting them into diastereoisomers by adding a chiral reagent, separating these isomers, and then reconverting them back into enantiomers. This procedure was first carried out by Louis Pasteur when he separated the sodium salts of (R)- and (S)- racemic acid.