# chemistry

posted by bubble

1)If 746.4 g of a substance is dissolved in 1723 g of benzene solvent, the freezing point of the solution is -9.19 oC. Calculate the apparent molar mass (g/mol) of substance.

2)
What mass ( g ) of the solvent water should be mixed with 0.008595 L of the solute ethylene glycol to prepare a solution that is 0.212 m ethylene glycol.

1. DrBob222

1) delta T = Kf*molality
Use this formula to determine molality.
Then molality = moles/kg solvent will determine moles.
Then moles = g/molar mass will determine molar mass.

2)Remember the definition of molality = mols solute/kg solvent. You will need the density of ethylene glycol to convert L in the problem to grams and the molar mass to convert to moles.

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