A sample of a substance containing only magnesium and chlorine was tested in the laboratory and was found to be composed of 74.5% chlorine by mass. If the total mass of the sample was 190.2 grams, what was the mass of the magnesium?

Question

Noah Aldrich · Accepted Answer

#"Mass of magnesium"# #=# #25.5%xx190.2*g=48.5*g#

In a binary compound, #XY#, if #%X# is given, then, clearly, #%Y=100-X%# with respect to mass.

So we take that figure and multiply it by the mass of the sample to give under #50* g#.

Keep in mind that you could create an empirical formula for the compound using the provided data.

Avery Adams · Answer

undefined The mass of magnesium in the sample can be calculated by subtracting the mass percentage of chlorine from 100% to find the mass percentage of magnesium, then using that percentage to find the mass of magnesium in the sample.

Mass percentage of magnesium = 100% - 74.5% = 25.5%

Mass of magnesium = (25.5/100) * 190.2 grams = 48.51 grams