How do you calculate the percentage of calcium in calcium carbonate, #CaCO_3#?

1 Answer

40.04 %

Explanation:

You take the atomic mass of calcium over the atomic mass of #CaCO_3# and multiply it by 100 to get the percentage.

The mass of #Ca# is 40.078 g; the mass of #C# is 12.01 g, and the mass of #3O#
is 47.997 g (#"15.999 g" xx 3#).

Add all the masses together to get a total mass of 100.085 g.

So, #("40.078 g")/("100.085 g") = "0.4004 or 40.04 %"#.