How many formula units of CaCO3 are present in 4.72 n of calcium carbonate?

The number of formula units is calculated with the use of Avogadro's constant. That is, on the basis of Avogadro's law:

1 mole = 6.02 * 10²³ formula units

4.72 moles = x formula units

By cross multiplication, we get:

4.72 moles * 6.02 * 10²³ formula units / 1 mole = 2.841 * 10²⁴ formula units.

Thus, the number of formula units of CaCo₃ that are found in 4.72 moles calcium carbonate is 2.841 * 10²⁴.