The Safe Drinking Water Act (SDWA) sets a limit for mercury—a toxin to the central nervous system—at 0.0020 ppm by mass. Water suppliers must periodically test their water to ensure that mercury levels do not exceed this limit. Suppose water becomes contaminated with mercury at twice the legal limit (0.0040 ppm). How much of this water would a person have to consume to ingest 50.0 mg of mercury?

Video transcript

Hello everyone today. We are being given the following problem and asked us all for it. It says a concentration of four PPM or parts per million of chlorine is considered to be safe drinking water. How much water must a person consume in order to intake one g of chlorine first, you want to make note that PPM Parts per million is in units of g over 10 to the 6th g. We didn't take what we're given. We have one g of chlorine. And we want to use the molar mass ratio which between chlorine and water. We say that for every four g of chlorine we have g of H 20. We then must use how many grams per milliliter. There are in one g of water. We have one mil liter of water as well. And then finally we have to go from middle leaders to leaders and we can use the following conversion factor of one. Middle leader is equal to one times 10 to the negative third leaders of H 20. And once our units cancel, We note that we have a final answer of 250 leaders. I hope this helped. And until next time