Lead is the least toxic metal ion to fish compared to zinc, copper, and mercury ions. Fish can tolerate a lead concentration slightly above 0.850 mM. What is this concentration in ppm? Assume the density of the water is 1.00 g/mL.

Question

Quizplus · Accepted Answer

To convert the concentration from mM (millimoles per liter) to ppm (parts per million), we use the formula: ppm = (mg/L) / (density of water in g/mL). Given that the density of water is 1.00 g/mL, 1 liter of water weighs 1000 g. A concentration of 0.850 mM means 0.850 millimoles of lead per liter of water. The molar mass of lead (Pb) is approximately 207.2 g/mol. Therefore, 0.850 mM of Pb is equivalent to 0.850 mmol/L * 207.2 mg/mmol = 176.12 mg/L. Since the density of water is 1.00 g/mL, this directly translates to 176 ppm.

Lead Is the Least Toxic Metal Ion to Fish Compared