If you knew that you had either cyclohexane or cyclohexene in the lab but weren't sure which, how could you determine which it was?

Question

Thanks from Sheryl

Since I'm not an organic chemist I would think of an organic test LAST. Density, refractive index, and boiling points of both are too close to differentiate. However, the melting point of cyclohexane is +6 something and cyclohexene is -103 something. +6 should be easily attainable in the lab. That's what I would do. Check out those numbers in your tables. Everyone will tell you not to rely on physical properties but pure samples can tell you a lot. If not that I would try IR and/or NMR. The double bond should be visible in IR. And NMR should show a CH group which the cyclohexane doesn't have. The books tell me n-bromosuccinimide (NBS) will brominate cyclohexene MUCH faster than it will cyclohexane but nothing about how much faster or if the rate is sufficiently different to differentiate between the two.