Lauryl alcohol is obtained from coconut oil and is used to make detergents. A solution of 5.00 g of lauryl alcohol in 100.0 g of benzene freezes at 4.2 oC. What is the approximate molar mass of lauryl alcohol. Refer to the text book for the boiling point of pure benzene. (80 C)

Question

Lauryl alcohol is obtained from coconut oil and is used to make detergents.  A solution of 5.00 g of lauryl alcohol in 100.0 g of benzene freezes at 4.2 oC. What is the approximate molar mass of lauryl alcohol. Refer to the text book for the boiling point of pure benzene. (80 C)

So this is what I have so far
5.5 C-4.2 C = 1.3 C

DrBob222 · Answer

OK. You've solve so far for delta T delta T = Kf*molality Substitute and solve for molality. m = mols/kg solvent Sove for mols. mols = grams/molar mass You hae grams and mols, solve for molar mass.