Longest Chain The number of carbons in the longest chain determines the base name ethane, hexane. Listed in Table 3.2 page 81 If there are two possible chains with the same number of carbons use the chain With the most substituents CH-CH2-CH 3 CH H3 C-CH2- C—CH-→CH2CH2CH3 CH Chapter 3Chapter 3 6 Longest Chain • The number of carbons in the longest chain determines the base name: ethane, hexane. (Listed in Table 3.2, page 81.) • If there are two possible chains with the same number of carbons, use the chain with the most substituents. C CH3 CH2 CH3 CH CH2 CH2 CH3 CH CH2 CH3 H3C H3C =>