A 1.60 g sample of a mixture of naphtalene, C10H8. and anthracene

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SUMMARY

The discussion centers on determining the mass percentage composition of a mixture containing naphthalene (C10H8) and anthracene (C14H10) dissolved in benzene (C6H6). Given a 1.60 g sample and a freezing point depression of 2.81°C, the problem requires calculating the individual mass percentages of naphthalene and anthracene in the original mixture. The freezing point of pure benzene is 5.51°C, and its cryoscopic constant (Kf) is 5.12°C kg/mol, which are crucial for solving the problem accurately.

PREREQUISITES
  • Understanding of colligative properties, specifically freezing point depression.
  • Familiarity with the concept of molality and its calculation.
  • Knowledge of how to apply the formula for freezing point depression: ΔTf = Kf * m.
  • Basic skills in algebra for solving equations involving mass and molar mass.
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  • Study the calculation of freezing point depression using Kf values.
  • Learn how to determine molality from mass and volume of solvents.
  • Explore methods for separating and analyzing mixtures in organic chemistry.
  • Investigate the properties and applications of naphthalene and anthracene in chemical processes.
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Chemistry students, particularly those studying physical chemistry and colligative properties, as well as educators preparing lessons on freezing point depression and mixture analysis.

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Homework Statement


"A 1.60 g sample of a mixture of naphtalene, C10H8. and anthracene, c14H10 is dissolveed in 20.0g of benzene, C6H6. The freezing point of the solution is 2.81C. Pure Benzene freezes at 5.51C and has a Kf = 5.12C kg/mol. Determine the composition (mass percentage) of naphthalene-anthracene mixture?"

my question is are they asking us for the easy mass composition of the Nap. and ant. mixture over the total mass or are they asking me to find the actual mass % between nap and ant., as in how many grams out of the 1.6 is the mass of nap?

Homework Equations





The Attempt at a Solution


if the question is as easy as it seems:
1.6/21.6 = 7.4%
 
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No, they ask about % composition of the original mixture - how many percent of naphtalene, how many perecent of anthracene.

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