Question

Calculate the mass in grams of calcium carbonate present in a 50.00 mL sample of an aqueous calcium carbonate standard, assuming the standard is known to have a hardness of 75.0 ppm (hardness due to CaCo3)

density of the sample is .9977 g/mL and the molar mass of calcium carbonate is 100.0 g/mol

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Answer 1

The units of ppm means parts per million. Also, It is equivalent to milligrams per liter. It is one way of expressing concentration of a substance. It usually used to describe the concentration of something in water or soil. We calculate the mass of CaCO3 as follows:

Mass = 75 mg/L (.050 L) = 3.75 mg CaCO3