How many lines will you see in the 1c (proton-decoupled carbon) spectrum of benzene; ethanol, 2,3- dimethyl-2-butene. Solution Benzene = 1 Ethanol = 2 2,3-dimethyl-2-butene = 2 --------------------------------------------------------------------------------------------------------------------- In proton-decoupled 13C spectrum shows no splitting of C center, it consists of single peaks corresponds to each set of equivalent carbons in a molecule. Benzene = No. of equivalent carbon is one so number of lines = 1 (128 ppm) Ethanol = No. of equivalent carbon is two, CH3, CH2OH, so number of lines = 2 (18, 58 ppm) 2,3-dimethyl-2-butene = No. of equivalent carbon is two, CH3, CH, so number of lines = 2 (18, 123 ppm) .