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In experiment 8 (Molar Mass Determination by Depression By Freezing Point) Why is the "molar mass"...

In experiment 8 (Molar Mass Determination by Depression By Freezing Point) Why is the "molar mass" is calculated and not the "molecular weight?" In General Chem 2.

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The determination with the depression of freezing point involves determination of the molality i.e; the number of moles of solute per kg of the solvent ( ∆Tf = Kf × m).

So we get the mass of the substance in terms of moles which indicates the molar mass having units mol/g or mol/kg.

Molar mass and molecular weight are almost same in values but there definition and units are different, as molecular weight is expressed in atomic mass unit and it describes the mass of the molecule irreseirresp of moles and it is the mass of a substance relative to 1/12th mass of 12C.

So the determination of molar mass over molecular weight lies in the principles of freezing point depression itself.

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