The maximum contaminant level (MCL) set by the EPA of thallium in drinking water is 0.0020 mg/L. Convert the MCL of thallium from milligrams per liter to parts per billion (ppb). converted MCL of thallium: ppb A farmer recently dug a new well for his property. He sends a 16.0 mL sample of the well water to the EPA to be tested for the presence of thallium. What is the maximum amount of Tl (in μg) that can be present in this 16.0 mL sample based on its MCL? maximum amount of Tl : μg Suppose the farmer rethinks his plan and digs a new well on the other side of his property. He sends in a new 16.0 mL sample. After testing, the EPA determines that the sample of water contains 0.00164 μg/mL Tl. Is the thallium level of the new well water safe to consume? yes not enough information no

Question

James Bailey

Chemistry

23 November, 15:03

The maximum contaminant level (MCL) set by the EPA of thallium in drinking water is 0.0020 mg/L. Convert the MCL of thallium from milligrams per liter to parts per billion (ppb). converted MCL of thallium: ppb A farmer recently dug a new well for his property. He sends a 16.0 mL sample of the well water to the EPA to be tested for the presence of thallium. What is the maximum amount of Tl (in μg) that can be present in this 16.0 mL sample based on its MCL? maximum amount of Tl : μg Suppose the farmer rethinks his plan and digs a new well on the other side of his property. He sends in a new 16.0 mL sample. After testing, the EPA determines that the sample of water contains 0.00164 μg/mL Tl. Is the thallium level of the new well water safe to consume? yes not enough information no

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Answers (1)

Know the Answer?

Marcelo Griffith · Answer 1

a) C Tl = 2 ppb

b) mass Tl = 0.032 μg

c) yes, 0.00164 μg/mL < 0.02 μg/mL, then the water can be safely consumed.

Explanation:

MCL (EPA) = 0.0020 mg/L (ppm)

a) C Tl = 0,002 ppm * (1000ppb/ppm) = 2 ppb

b) 16mL * (L/1000mL) = 0.016 L

⇒ m Tl = 0,016 L * 0.002 mg/L = 3.2 E-5 mg Tl * (1000μg/mg) = 0.032μg Tl

c) C Tl = 0.00164 μg/mL

∴ according to MCL for 16 mL of sample, the maximum amount allowed is the 0.032μg Tl

⇒ the Tl concentration for 16mL of sample, would be:

⇒ C Tl = 0.032μg Tl / 16 mL = 0.02 μg Tl/mL

∴ the new sample concentration (0.0016 μg Tl/mL) is less than the maximun concentration allowed by MCL (0.02μg Tl/mL) for that amount of sample; then the water from that well can be safely consumed.