A #2.03*g# mass of calcium salts contains #1.33*g# calcium carbonate. What is the #%# calcium carbonate; and what is the percentage by mass of of calcium in calcium carbonate?

1 Answer
anor277
Mar 9, 2017

#"%calcium carbonate (by mass)"=(1.33*g)/(2.03*g)xx100%=65.5%#

#"%calcium (by mass)"=26.2%#

Explanation:

So we have the #"%calcium carbonate, "m/m#. We are not finished yet, because we have to address the percentage by mass of calcium metal in calcium carbonate:

#%Ca=(40.08*g*mol^-1)/(100.09*g*mol^-1)=40%# with respect to calcium carbonate.

And thus the #%Ca# IN THE SAMPLE

#=(1.33*g)/(2.03*g)xx(40.08*g*mol^-1)/(100.09*g*mol^-1)xx100%=26.2%#

We have assumed that ALL of the calcium metal is present as the carbonate.

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