To determine the incorrect statement regarding chirality, let's analyze each option:$\\$Option 1: $$SN$_1$ reaction yields a 1:1 mixture of both enantiomers.$\\$• In an $$SN$_1$ reaction, the formation of a planar carbocation intermediate allows attack from either side,$\\$ leading to a racemic mixture (1:1 mixture of enantiomers). This statement is correct.$\\$Option 2: $$The product obtained by an SN$_2$ reaction of a haloalkane having chirality at the reactive site shows inversion of configuration.$\\$• An $$SN$_2$ reaction involves a backside attack, resulting in inversion of configuration at the chiral center.$\\$ This statement is correct.$\\$Option 3: $$Enantiomers are superimposable mirror images of each other.$\\$• Enantiomers are actually non-superimposable mirror images of each other.$\\$ This statement is incorrect.$\\$Option 4: $$A racemic mixture shows zero optical rotation.$\\$• A racemic mixture contains equal amounts of both enantiomers, which cancel each other's optical activity,$\\$ resulting in zero optical rotation. This statement is correct.$\\$Therefore, the incorrect statement is Option 3.