Final answer:
There are 18 oxygen atoms in 2 formula units of Al2(SO3)3.
Step-by-step explanation:
The formula for 2 formula units of Al2(SO3)3 is Al2(SO3)3.
To determine the number of oxygen atoms, we need to find the number of oxygen atoms in 1 formula unit of Al2(SO3)3.
In 1 formula unit, there are 3 sulfur atoms and each sulfur atom is bonded to 3 oxygen atoms, so there are a total of 9 oxygen atoms in 1 formula unit.
Since we have 2 formula units, we can multiply the number of oxygen atoms in 1 formula unit by 2:
9 oxygen atoms x 2 = 18 oxygen atoms.
Therefore, there are 18 oxygen atoms in 2 formula units of Al2(SO3)3.