<p>How difficult would it be to go from Aerospace in undergrad to ChemE in grad?</p>
<p>You'd likely have to take many of the undergrad courses for ChemE.</p>
<p>Would I have to take them before I got accepted for ChemE grad, or afterwards?</p>
<p>It would be wise to take a few of the core while an undergrad or else you would have to take them as a grad student. One school, however, where you wouldn't have to take any chemE undergrad is MIT. Their rules are clear- you just have to be able to pass the chemE graduate courses. This is assuming, of course, if you can get into MIT. But even so, it would still be wise to take some chemE undergrad courses because you will be lacking some fundamental knowledge. </p>
<p>May I ask, why you want to switch? Aerospace to chemical is kind of drastic.</p>