How many moles of CaCO3 are there in an antacid tablet containing 0.520 g CaCO3?

Question

How many moles of CaCO₃ are there in an antacid tablet containing 0.520 g CaCO₃? How many formula units of CaCO₃ are in this tablet?

Answer 1

Molar mas CaCO₃ = 100.09 g/mole

To convert 0.520 g to moles, we can use dimensional analysis:

0.520 g x 1 mole/100.09 g = 0.005195 moles = 0.00520 moles (to 3 significant figures)

To find the number of formula units, we again can use dimensional analysis and the fact that there are 6.02x10²³ formula units in 1 mole:

0.00520 moles CaCO₃ x 6.02x10²³ form.units/mole = 3.13x10²¹ formula units