Question

Find the concentration of calcium in ppm in a 3.5g pill that contains 40.5mg of ca?

Answer 1.16ppm


Bob helps me

Answer 1

I don't know if I can help or not. The answer is not 1.16 ppm
40.5 mg is 0.0405 g
0.0405 g/3.5g = 0.0116 g Ca/g which is
(0.0116 g Ca/g) x (1E6/1E6) = 0.0116E6/1E6 = 1.16E4/1E6 = 1.16E4 ppm.

Answer 2

why do we multiply by 1e6?

Answer 3

1.167

Answer 4

I apologize for my mistake earlier. Bob's calculation is correct.

To answer your question, we multiply by 1e6 to convert the concentration from grams per gram to parts per million (ppm), which is a common unit for expressing small concentrations. One ppm is equivalent to one milligram per liter or one milligram per kilogram. Since we have the concentration in grams per gram, we need to multiply by 1e6 to convert it to ppm.