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Question: A student tries to separate a liquid mixture of ethanol and water using fractional distillation. Can the student obtain 100 percent pure ethanol from a mixture that starts with 95.6 percent ethanol and 4.4 percent water by mass? Explain why or why not based on azeotropic behavior. Step 1: Identify the given composition of the mixture, which is 95.6 percent ethanol and 4.4 percent water by mass. Step 2: Recognize that this specific 95.6 percent ethanol and 4.4 percent water mixture forms a minimum boiling azeotrope at standard pressure, boiling at a constant temperature of 78.15 degrees Celsius. Step 3: Recall the definition of an azeotrope, which states that the liquid mixture and its vapor have the exact same composition at the boiling point. Step 4: Conclude that because the vapor has the exact same percentage of ethanol and water as the remaining liquid, fractional distillation cannot alter the composition further. Step 5: Final Answer: No, the student cannot obtain 100 percent pure ethanol because the azeotrope boils at a constant composition, making complete separation by simple distillation impossible.