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A 1.875 g sample of pyrazine was dissolved in 25.00g of water, producing a solution that freezes at -1.55 C. Assume the solution behaves ideally. Kf(H2O)=1.86 C/molality.
What is the experimental molecular weight of pyrazine?

  • college chemistry -

    delta T = Kf*molality
    Solve for molality

    molality = moles/kg solvent
    Solve for moles

    moles = grams/molecular weight
    Solve for molecular weight.

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