If you are converting the mass of a substance from milligrams/kilograms (mg/kg) to parts per million (ppm), then the ratio is 1:1, and no conversion is necessary. Therefore, 1 mg/kg is the same as 1 ppm because 1 milligram is equal to 0.001 grams while 1 kilogram is equal to 1,000 grams. So, if you divide 0.001 by 1,000, then the result is 0.000001, which is a millionth of a gram, making it the same as 1 part per million.
This logic only works for mass conversions. If you are attempting to convert mg/kg of volume or moles to ppm, then the substances being used will change the outcome. In the case of both volume and moles, ppm is found by using the formula c/s where "c" is the volume or moles of the compound divided by "s," which is the volume or moles of the solution.
1. Ensure that the parts per million value you are converting is a mass per mass value. This is the typical usage of parts per million. If you are making a conversion to mg/kg (which
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ppm stands for parts per million. mg/kg is equivalent to ppm because there are 1 million milligrams in 1 kilogram. Therfore if you had something that had 2.8 ppm NaCl in soil, you
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ppm x 3to the power of 6= kg.
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The answer to your math question is that 20013 mg converts to 0.020013 kg. Thank
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