A tailing pond at a mine contains a million liters of water and 10 kg of the very toxic substance mercuric chloride (HgCl2), mixed evenly throughout the water in the pond. Water from the mining operation flows into the tailing pond at a rate of 10 liters per second, and each liter of water is contaminated with 1 mg of HgCl2, which mixes instantly into the pond water upon arrival. Unfortunately, the mining company does absolutely nothing to remove the mercury from the pond water, and allows it to exit the pond unfiltered, at the same rate of 10 L/sec. How much HgCl2 is found in a liter of pond water after this process continues for (a) an hour (b) a day (c) If the process were to go on indefinitely, how much HgCl2 would the pond end up containing?
The Attempt at a Solution
I know how to do differential equations if they are given, but I cannot seem to construct one from the text above. That is the extent of my attempt at a solution, because I don't even know where to start.
Thanks in advance!