Which of the diethylbenzene isomers (ortho, meta, or para) corresponds to each set of 13c nmr spectral data?

[a] 13c nmr signals: 15, 26, 126, 128, and 142 ppm
[b] 13c nmr signals: 16, 29, 128, and 141 ppm
[c] 13c nmr signals: 16, 29, 125, 127.5, 128.4, and 144 ppm

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.