<p>There is a lot to CS that many people outside of CS don’t realize/associate with CS. If your primary interest is in ChemE, odds are you don’t really understand what a major in CS would entail, and if you did, you wouldn’t be considering it. I’m assuming this is the case; if not, feel free to ignore what follows.</p>
<p>CS programs typically include coursework in a variety of areas. Most people realize that CS programs will usually require extensive training in programming using one or more languages, such as Java, C/C++, or more exotic languages like Scheme or Python. CS programs also include a variety of coursework in theory/mathematics (discrete mathematics, formal language theory, automata theory, complexity theory, algorithms, etc.), systems (operating systems, networks, etc.), applications (programming languages, databases, graphics, etc.), software engineering (software design, software process, software modeling, quality assurance, etc.), and architecture/hardware (computer architecture, assembly language, digital logic, etc.). To be good enough to graduate with a major in CS, you have to prove that you have developed a fairly rigorous understanding of most of these things (applications courses, especially, tend to vary from school to school)… many engineering/science people who wish to study CS do not necessarily want to learn about all of this stuff, but rather about computer programming and how it can be used to solve problems in their domain.</p>
<p>Even for that, CS programming classes may not be particularly well-suited. Learning a progamming language is something that anybody smart enough to get into a STEM discipline can do as a hobby in their own time. You can find books that deal with programming the problems you want to solve, and look at how code works. You can use this as a springboard into writing your own stuff. Rather than learning the difference between e.g. selection and heap sort, you can learn what libraries to use when sorting data. CS studies computation at a much more fundamental level than most non-CS majors are unlikely to care about or grasp.</p>