1. Calculate the molar mass of SnO2:
Molar mass of Sn = 118.710 g/mol
Molar mass of O = 15.999 g/mol
Molar mass of SnO2 = (1 x 118.710 g/mol) + (2 x 15.999 g/mol) = 150.698 g/mol
2. Convert the given mass (22.4 g) to moles:
Moles of SnO2 = Mass / Molar mass
Moles of SnO2 = 22.4 g / 150.698 g/mol
Moles of SnO2 = 0.1488 mol
3. Calculate the number of formula units using Avogadro's number:
Avogadro's number = 6.022 x 10^23 formula units/mol
Number of formula units = Moles of SnO2 x Avogadro's number
Number of formula units = 0.1488 mol x 6.022 x 10^23 formula units/mol
Number of formula units = 8.956 x 10^22 formula units
Therefore, there are 8.956 x 10^22 formula units in 22.4 g of SnO2.
