I did a lab where I put about a gram of an unknown organic compound in a test tu

Question

I did a lab where I put about a gram of an unknown organic compound in a test tube with about 10.5 grams of Naphthalene and suspended the test tube in boiling water until it melted as a solution at 95 degrees celcius and then timed it as it cooled and found it's freezing point to be about 72 degrees Celcius.

I'm supposed to find out what the unknown organic substance is. Through change of Tf = imKf, and a little algebra, I found the molar mass to be 77.89 g/mol.

I'm very confident in my math in finding this molar mass, but, knowing I could have been off by a few degrees in finding the freezing point, The molar mass might be a little different.

I need to know what organic compound soluble in naphthalene has a molar mass of about 77.89g/mol. I know benzene is one possibility and I'm tempted to make that my answer, but I remember the solute being a light yellow-greenish colored crystal/powder thing.

What greenish organic compound has a molar mass of about 77.89g/mol +/-2 or something (and is soluble in naphthalene)?

Explanation / Answer

Benzene may not be present since Benzene has MP of 5.5 C and BP at 80 C.

Its tough to find molecule just by mol wt .

Molecule must be non polar since it is solubel in napthalene.

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