An aqueous solution contains 64.0 g of ethanol (C₂H₅OH)in 122.0 g of solution.What is the mole fraction of ethanol in the solution? A)0.301 B)0.432 C)0.205 D)0.698 E)0.317

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Quizplus · Accepted Answer

The mole fraction of ethanol is calculated by dividing the moles of ethanol by the total moles of the solution. First, calculate the moles of ethanol: $ \frac{64.0 \, \text{g}}{46.07 \, \text{g/mol}} = 1.39 \, \text{moles} $ (molar mass of ethanol $C_2H_5OH$ is approximately 46.07 g/mol). The mass of water is $122.0 \, \text{g} - 64.0 \, \text{g} = 58.0 \, \text{g}$. The moles of water are $ \frac{58.0 \, \text{g}}{18.015 \, \text{g/mol}} = 3.22 \, \text{moles} $. Total moles = $1.39 + 3.22 = 4.61 \, \text{moles}$. Mole fraction of ethanol = $ \frac{1.39}{4.61} = 0.301$.

An Aqueous Solution Contains 64