解:(1) ethane c- H bond 2zc vm MM N2/2m=4.12 M+M 6.023×1023 5.1×105 2×3.14159×298×10010.9237 306lcm- (2) Acetylene C-H bond 同上,M=12X1(12+1)=0.9237,=3292cm1. (3)Ethane C-C bond M=6,G=1128cm1 (4)Benzene C-C bond G=1466cm1 5)CH3CN,C三N,σ=2144cm1解：（１）ethane C-H bond: 1 5 1 0 2 3 1 2 1 2 1 2 1 2 3061 0 9237 5 1 10 2 3 14159 2 998 10 6 023 10 2 4 12 2 − =      = = + = = cm N c M M M M M M k c N A A . . . . . , / . / /     (2) Acetylene C-H bond 同上，M=12x1/(12+1)=0.9237, =3292cm-1 . (3)Ethane C-C bond. M=6, =1128cm-1 (4)Benzene C-C bond  =1466cm-1 (5) CH3CN, C≡N,  = 2144cm-1