Answer:

Explanation:
Given
Compound: 
Required
Determine the equivalent mass
In the above compound, we have: 2 Al and 3 (O)
The atomic mass of Aluminium is:

The atomic mass of Oxygen is:

So, the equivalent mass is:



Sulfur has the same amount, like all the other elements in group 16, has six valence electrons.
Answer:
Explanation:
Hello, since the Gibbs' phase rule states the following equation:

Whereas C is the number of components and P the present phases, you answers are:
1. F=1-2+2=1.
2. F=2-2+2=2.
3. F=2-2+2=2.
Best regards.