The structural formula of 2, 3, 4-trichloro pentanoic acid is given below. CH3∣H−C∗−Cl∣H−C∗−Cl∣H−C∗−Cl∣C∣∣O−OH Number of optical active isomers =2n where, n = number of asymmetric carbon atom. 2, 3, 4-trichloropentanoic acid has three asymmetric carbon atoms. So, number of optical active isomers =23∴ Number of optical active isomers = 8