How do you find the percentage composition of a compound that contains 17.6 g of iron and 10.3 g of sulfur? The total mass of the compound is 27.9 g.
1 Answer
Here's how you can do that.
Explanation:
Your goal here is to figure out the mass of iron and the mass of sulfur present in exactly
The problem provides you with the mass of iron and with the mass of sulfur present in
To do that, set up the known composition of the compound as a conversion factor.
To find the number of grams of iron present in
#"17.6 g iron"/"27.9 g compound"#
You will end up with
#100 color(red)(cancel(color(black)("g compound"))) * "17.6 giron"/(27.9color(red)(cancel(color(black)("g compound")))) = "63.1 g iron"#
To find the mass of sulfur present in
#100 color(red)(cancel(color(black)("g compound"))) * "10.3 g sulfur"/(27.9color(red)(cancel(color(black)("g compound")))) = "36.9 g sulfur"#
or use the fact that the compound contains only iron and sulfur to say that the mass of sulfur will be equal to
#"100 g compound " - " 63.1 g iron = 36.9 g sulfur"#
You now know the mass of iron and the mass of sulfur present for every
#"63.1% iron"# #"36.9% sulfur"#
Here
The values are rounded to three sig figs.