The safe drinking water act (sdwa) sets a limit for mercury-a toxin to the central nervous system-at 0.002 mg/l. water suppliers must periodically test their water to ensure that mercury levels do not exceed 0.002 mg/l. suppose water becomes contaminated with mercury at twice the legal limit (0.004 mg/l). part a how much of this water would have to be consumed to ingest 0.150 g of mercury

3.75 * 10^7 g of this water would have been consumed.

Explanation:

ppm represents parts per million.

ppm = (mass solute / mass solution ) *10^6

⇒It is a way to express the concentration of very dilute solutions.

For this situation we have:

ppm = (grams of mercury / grams of solution ) * 10^6

0.004 = (x grams of mercury / 1g of solution) 10^6

x = 0.004 /10^6

x = 4 *10^-9 g Mercury

This mass of mercury is per gram of solution. In the next step, we can calculate the amount of solution (water plus mercury) that would have to be ingested to ingest 0.150 g of mercury

0.150 g of Hg * (1g of solution/ 4 *10^-9 g Mercury)= 3.75 *10^7

3.75 * 10^7 g of this water would have been consumed.

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.