Solving Using PPM (Parts Per Million)

Key Questions

  • In order to calculate the parts per million you will need to know how many mg of solute is dissolved in 1000g (1L) of water.

    #(0.001g)/(1000g)# = 0.000001
    Multiplying 0.000001 by 1,000,000 gives a result of 1ppm.

    Here is a video discussing this type of calculation. In the video, the number of moles of barium present in a 1L sample of water with a barium concentration of 2ppm is calculated.

    2 ppm is the maximum allowable level for barium in drinking water in the US as established by the EPA .

    Video from: Noel Pauller

  • Answer:

    It's often used to measure contaminants, but there's other applications.


    When you read about an article about air pollution or water pollution, you'll often see it refer to the concentration of contamination in ppm.

    here's a NASA article talking about the concentration of CO2 in the atmosphere reaching 400ppm.

    You can also get a water quality tester to see the concentration of foreign particles in the water.

  • ppm is parts per million.

    Just as a percentage is 1 part in 100 ppm is one part in a million. It's used to avoid very small numbers.

    E.g a gas in the atmosphere could be #0.03%#

    To convert ppm you x by #10^4# to give 300ppm.