Measuring Pollutants Flashcards
1
Q
What is concentrations of pollutants in the air measured in?
A
ppb (parts per billion) or ppm (parts per million).
2
Q
Give an example of measuring pollutants.
A
A sulfur dioxide concentration of 16ppb means that in every one billions molecules of air, 16 molecules will be sulfur dioxide.
3
Q
Why when measuring the concentrations of pollutants is it important to repeat the measurements?
A
For example, the concentration of nitrogen oxides from cars may change depending on the time of day (the amount of traffic and weather).
4
Q
What does repeating measurements allow a chemist to do?
A
Calculate a mean, this will give a good estimate of the true value of the concentration of the pollutant.
