A very dilute mixture is formulated by dissolving x1 moles of solute into x2 moles of solvent. Under these conditions, the mole fraction of the solute is roughly equal to_________________?
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Answer: A. x1/x2
Explanation
In a very dilute mixture, the number of solute moles is extremely small compared to solvent moles. Mathematical simplification allows the solute mole fraction expression to omit the solute term from the denominator. This reduction turns the complex fraction into a simple ratio of solute moles divided by solvent moles. Mole fractions represent the ratio of a component moles to the total moles of all mixture components. Dilute solutions contain vast excesses of solvent molecules surrounding very few dissolved solute particles. Approximations simplify complex thermodynamic calculations without introducing significant errors in dilute solution analysis.
Chemical engineers frequently apply dilute solution approximations when studying trace contaminants in aqueous streams. Colligative property calculations often rely on these simplified mole fraction expressions for clarity. Environmental engineering models use dilute approximations to track pollutant dispersion in large water bodies. Option B inverts the ratio, which would incorrectly imply that solute moles exceed solvent moles vastly. Option C subtracts the ratio from one, yielding a value representing the solvent mole fraction instead. Option D divides one by solvent moles, completely ignoring the presence of solute moles in the numerator.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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