Suppose that a semiconductor plant uses 1,000,000 liters of city water per day to keep its production line of semiconductors runing. Also let's suppose that the water supplied to the plant contains 100 parts per million of Magnesium ions. Calculate the amount of Magnesium and water entering and leaving the filtration process.


In order to do this problem, first we must understand what "parts per million" means mathematically.Parts per million (ppm)is a description of the ratio of particles in a solution to the total amount of solution by mass. A example of this is percentages. 5% is the same as saying 5 per hundred, or 5 parts per hundred.

To calculate the amount of Magnessium in the tap water stream, we have the ratio of parts per million to the amount of water. Since the amount of water is in liters, We have to multiply the total amount of water by its density and convert to kilograms.

Click where you think the 1,000,000 liters will go.

Mg2+WaterTotal mass
Tap Water
1,000,000
Ultra-pure Water
Bottoms

2007 Arizona Board of Regents for The University of Arizona