00:01
To compute parts per million in mass, all we have to do is to take the mass of the soil and divide by the mass of solvent and multiply that by a million.
00:22
That's why it's called parts per million.
00:26
Both have to be in same units because ppm is unitless.
00:34
It has no dimension okay all right so let's do this for the lead we know that the concentration or the mass of lead in this sample is 192 micrograms okay in microgram is the equivalent of 10 to the minus 6 grams so we can write 192 times 10 to the minus 6 grams okay and that's going to be divided by the mass of water.
01:07
All right, then we don't have the mass of water, we actually have the volume.
01:13
So we have the volume of water, which is 2 .6 liters.
01:17
But remember that for pure water or very diluted solution, as is this case, the one liter of water is approximately one kilogram.
01:29
So we can say that this is 2 .6 kilograms...