What sort of research experience does a college or university expect a professor to provide an undergraduate?
Faculty in such situations might be expected to provide research experiences commensurate with the size and scope of the institution. Undergraduates usually cannot devote the time to a project that a graduate student does, so the outcomes are different. Publications are not generally expected; conference presentations are more common. Most importantly, the undergraduate gets experience working on a complex problem and develops transferable research skills. What the faculty member gets is not the same as what he or she would get from graduate students.

What an undergraduate does as research depends on the facilities, infrastructure, and culture of the institution. At a major research institution, undergraduates should be working on the same types of problems graduate students work on, but perhaps in a more limited scope. When I was a grad student, we had several undergrads in our lab, one of whom was grad student quality and got some publications. The others contributed valuable (if not always publishable) work to our projects. 

At a smaller institution that maybe does not have a graduate progran (like where I am now), you give an undergraduate student work commensurate with the type of grants you are expected to write. My institution (and my department especially) does not emphasize pursuit of large external grants, and so the types of projects I can give to my students are more limited. At the undergraduate stage, the process is more important than the results. I regularly send my students to regional and national conferences, and I hope to eventually have them publish something, but I am not given low evaluation marks. However, if you are expected to apply for and get big grants, then your undergrads should be doing work at that level.

All in all, in the chemistry departments I have been a part of (large and small), most faculty have one or more undergraduates doing research and most undergraduates get the opportunity. However, not all undergraduates choose to, nor would their be enough opportunities to support them if they did. The onus is on the undergraduate to choose to do research, not on the professor to guarantee an opportunity is available to all students even if they do not want it.