The concentration of iodine in sea water is 60. parts per billion by mass. If one assumes that the iodine exists in the form of iodide anions, what is the molarity of iodide in sea water? (The density of sea water is 1.025 g/mL.)

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Quizplus · Accepted Answer

To find the molarity, convert parts per billion (ppb) to grams per liter using the density of sea water, then divide by the molar mass of iodide (I-). 60 ppb is 60 µg/L, which is 60 × 10^-6 g/L. The molar mass of iodide is approximately 127 g/mol. Molarity = (60 × 10^-6 g/L) / (127 g/mol) = 4.8 × 10^-7 M.

The Concentration of Iodine in Sea Water Is 60