How much math and chemistry have you learned? If you only know basic chemistry and some calculus, you could discuss the first-order ordinary differential equations that describe chemical kinetics. Often there are multiple reactions so there is a set of coupled differential equations. There might be analytical solutions, but you can also find numerical solutions using black-box solvers in software packages such as Matlab (or the free version, Octave). Especially if you find a compelling application this could be an interesting project that would be within reach of most second year students.
At a more advanced level, if you have learned physical chemistry then there are many options as it uses a lot of the same kinds of math that physicists use. Likewise, I had a roommate in college that took the 'honors' first year chemistry sequence and he learned group theory and applications to chemistry, which would be interesting.
jason