A 0.5376 g sample of an unknown compound is found to contain 0.3044 g of carbonate. Could this compound be calcium carbonate?

Calcium carbonate has the formula: CaCO3

From the periodic table:

mass of calcium = 40 grams

mass of carbon = 12 grams

mass of oxygen = 16 grams

Therefore,

molar mass of CaCO3 = 40 + 12 + 3 (16) = 100 grams

molar mass of carbonate = 12 + 3 (16) = 60 grams

One mole of calcium carbonate contains one mole of carbonate. Therefore, 100 grams of CaCO3 contains 60 grams of CO3.

If the 0.5376 grams of the unknown substance is CaCO3, then the amount of carbonate will be:

amount of carbonate = (0.5376*60) / 100 = 0.32256 grams

Based on the above calculations, the sample is not CaCO3