A 100.0 mL solution of ethanol that has density of 0.789 g/mL, contains 15.6 mL of iodine. The concentration of the aqueous solution is _____ ppm. (Density of iodine = 4.94 g/mL) A) 9.77 × 10⁵ B) 9.8 × 10⁷ C) 0.98 × 10⁹ D) 9.77 × 10⁶ E) 0.97 × 10³

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Quizplus · Accepted Answer

First, calculate the mass of iodine: $15.6 \, \text{mL} \times 4.94 \, \text{g/mL} = 77.064 \, \text{g}$. The total volume of the solution is $100.0 \, \text{mL} + 15.6 \, \text{mL} = 115.6 \, \text{mL}$. Convert this volume to liters: $115.6 \, \text{mL} = 0.1156 \, \text{L}$. The density of the solution is not directly relevant for calculating ppm, which is based on mass. Ppm is calculated as $\text{mass of solute (g)} / \text{total mass of solution (kg)} \times 10^6$. Since the question does not provide the total mass of the solution, we assume it's asking for the concentration of iodine in the ethanol solution before dilution. Thus, $77.064 \, \text{g} / 0.1156 \, \text{kg} \times 10^6 = 9.77 \times 10^5 \, \text{ppm}$.

A 1000 ML Solution of Ethanol That Has Density of 0