1) If a 12.7 cm³ sample of lake water is found to have 168.3 ng As, what is the concentration of arsenic in the sample in parts per
billion (ppb), assuming that the density of the lake water is 1.00 g/cm³?
2) One of the volunteers adjust hiring an on-site water treatment company to remove the arsenic from Lake. The company claims their process takes 2.01 days to remove 50.4 kg of arsenic from a water source. Calculate the total mass in kilograms of arsenic in lake that the company will have to remove the total volume of water in the lake is 0.77km^3.
3) Based on the company’s claim and the concentration of arsenic in the lake. How many years will it take to remove all of the arsenic from the lake? Assuming there are always 365 days in a year?