Question

Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 mg Hg/mL, what is the total mass in kilograms of mercury in the lake? ( the lake has a surface area of 100 mi^2 and an average depth of 20 ft. )

Answer 1

I would convert 100 square miles to cm^2, then multiply 20 feet (converted to cm) to find the volume in cc(mL). I'm assuming it is a rectangular shaped lake. It is some other shape you must use the appropriate formula to convert to volume.
Then 0.4 mg x volume in cc will give you the total Hg in mg. Convert mg to kg. The number I get is rather large.