dentify which one of the following isomers of C₆H₁₄ has the c-13 nmr below?
1) CH₃CH₂c(CH₃)3
2) CH₃CH₂CH₂ch(CH₃)2
3) CH₃CH₂CH₂CH₂CH₂CH₃
4) (CH₃)2chch(CH₃)2