Define racemic mixture.
Give IUPAC name of `CH_(3)-CH_(2)-overset(CH_(3))overset(|)(CH)-CHO`

Explanation

A solution in which both enatiomers of a compound are present in equal amounts is called a racemic mixture, or recemate. Racemic mixtures can be symbolised by a `(d//l)-or (pm)-` prefix in front of the substance's name indicating an equal (1:1) mixture of extro and laevo isomers. Also the prefix rac-(or racem-) or the symbols RS and SR (all in italic letters) are used. Since enantiomers have equal and opposite specific rotations, a racemic mixture exhibits no optical activity. Therefore, it is impossible to tell a racemic mixture apart from an achiral substance using polarimetry alone. The process by which a racemic mixture is formed from chiral materials is called recemisation. The separation of a racemate into its components, the pure enantiomers, is called a chiral reasolution. IUPAC name of compound is 2-methylbutanal.