I'm a little confused about this.. I was doing a question in the TPR orgo that had me rank CO, CO2 and CO3^2- bond length... It was intended to have you figure out which molecule had the most s character in its hybridized orbitals... I got it right just because I knew carbon monoxides chemical configuration..... my question is what if I hadn't known it... How would I be expected to know the C would triple bond to O and take on an extra electron? All things taught in normal prep books would have you believe that it would try to assume the configuration with the lowest Formal charge, and if CO double bonded with 2 lone pairs on Oxygen and one on carbon.... both atoms would have a formal charge of 0 In reality Carbon has a formal charge of -1 and Oxygen +1 Given what I know about electronegativity I would expect Oxygen to hog the electrons?? So is there any way to figure this out with normal MCAT knowledge or would I just have to had known CO behaves the way it does.... and if so are there other molecules the MCAT would expect me to know behave differently... ie: cyanide? Or would the structure be drawn in most cases if it didn't follow expected trends?