Brian —

Excellent question! I’m sure there are several others wondering that same thing, so I’ll have to remember to include some words in future articles that address that.

As a rule of thumb, chemists typically try not to interact with their chemicals, it usually results in bad things happening. For all the good chemicals we have (pharmaceuticals, alcohol, etc.), there are hundreds of bad ones, so in the lab, it’s typically not recommended to smell or feel the substances we work on.

Sight is a different story though, and visual observation to determine whether or not a reaction has occurred is very common. However, I’m not convinced (based on what I’ve read) that there are any visual differences between COT and, say, benzene or (perhaps more analogously) naphthalene.

What I am convinced of, though, are the analytical and spectroscopic differences. These are more nuanced and technical, but suffice it to say, they are more striking to a trained chemist.

Thanks for reading!