Question

Pheromones are compounds secreted by the females of many insect species to attract males. One of these compounds contains 80.78%C, 13.56%H, and 5.66%O. A solution of 1.41g of this pheromone in 9.23g of benzene freezes at 2.73 degrees C. what are the molecular formula and molar mass of the compound? the normal freezing point of pure benzene is 5.50 degrees C

Answer 1

delta T = Kf*molality
solve for molality

molality = mols/kg solvent
You know m and kg solvent, solve for moles.

moles = grams/molar mass
solve for molar mass.