Formula of the anionic detergent, sodium lauryl sulphate is

I) ${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_{11}{\mathrm{OSO}}_3^{-}{\mathrm{Na}}^{+}$ is sodium dodecyl (lauryl) sulphate; 

   ${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_{11}-$is the hydrophobic part and $-{\mathrm{OSO}}_3^{-}$ is the hydrophilic part $-{\mathrm{OSO}}_3^{-}$ is sulphate part.