I guess all these top programs (both finance and marketing, even accounting) care a lot about the economics background. With your chemistry background, it's hard to impress them. Guess both WashU and Kellogg your reference writers should have close connections, otherwise you won't have any chance. So many top econ applicants nowadays
Kaifu Zhang from CKGSB will move to CMU, so CMU does have strong senior and junior analytical modelers. People said Kaifu Zhang is one of the strongest analytical candidate in recent years' market if not the strongest.