Notifications
Clear all
0
28/12/2020 3:44 pm
Topic starter
Calculate the number of aluminium ions present in 0.051 g of aluminium oxide. (Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u)
1 Answer
0
28/12/2020 3:50 pm
Molar mass of Al2O3 = 2 × 27 + 3 × 16
= 54 + 48 = 102 g
∵ 102 g of Al2O3 contains
= 2 x 6.022 x 1023 Al3+ions
∴ 0.051 g of Al2O3 contains
= 2 x 6.022 x 1023/102 x 0.051
= 6.022 x 1020 Al3+ions