General Chemistry HW

Question

How many moles of CaCO₃ are there in an antacid tablet containing 0.500 g CaCO₃? 

______ mol CaCO3

How many formula units of CaCO₃ are in this tablet?

_______ formula units

Answer 1

To get the moles you need to determine the molar mass of CaCO₃

Ca = 1 x 40.1 = 40.1

C = 1 x 12 = 12

O = 3 x 16 = 48

100.1 g/mol

0.500 g CaCO₃ x 1 mol CaCO₃ = 5.00 x 10^-3 mole

100.1 g CaCO₃

To find the number of formula units remember that 1 mole is equal to 6.022 x 10²³ atoms

5.00 x 10^-3 mol x 6.022 x 10²³ atoms = 3.01 x 10²¹

1 mol