3.) Calculate the mass of oxygen gas that can be produced in the decomposition of 5.55 g of silver oxide.

This is what I did but is it right?... I need help with a few more btw to double check if i'm doing these right.

So here is what I did:
First: balance the equation
2 Ag2 O decomposes→ 4 Ag + O2

So, (btw I put parenthesis to make it visibly understandable if it helps)
5.55 g Ag2O * (1 mole Ag2O/ 139.868 g Ag2O) * (1 mol O2/ 1 mol Ag2O) * (31.998 g O2/ 1 mole O2) = 1.27 g O2.... since the ? is asking to calculate the mass of Oxygen gas (O2)

1.) what mass of zinc is needed to completely react with 4.00 g of silver nitrate?

2.) If excess ammonium sulfate reacts with 22.5 g of calcium hydroxide according to the following unbalanced chemical equation:
(NH4)2 SO4 + Ca (OH)2 → CaSO4 + NH3 + H2O
So,

I didn't check 2. #1 is not right but the system is correct.

1. Your calculation for molar mass of Ag2O is not right. The molar mass is closer to 231.8. You obtained that number by 1Ag + 2O and it should be 2Ag + 1 O or (2*107.9)+ 16 = about 231.8.

2. The second error is in convert mols Ag2O to mols O2. That should be
mols Ag2O x (1 mol O2/2 mols Ag2O) = ?

To calculate the mass of oxygen gas produced in the decomposition of silver oxide, you correctly balanced the equation:

2 Ag2O decomposes → 4 Ag + O2

Next, you used stoichiometry to convert the given mass of silver oxide (5.55 g) to the mass of oxygen gas.

Here's the calculation:

5.55 g Ag2O * (1 mol Ag2O / 139.868 g Ag2O) * (1 mol O2 / 1 mol Ag2O) * (31.998 g O2 / 1 mol O2) = 1.27 g O2

So, your calculation is correct, and the mass of oxygen gas produced in the decomposition of 5.55 g of silver oxide is 1.27 g.

Now, let's move on to the other questions you have:

1.) What mass of zinc is needed to completely react with 4.00 g of silver nitrate?

To solve this problem, you'll need to balance the chemical equation for the reaction between zinc and silver nitrate:

Zn + 2 AgNO3 → Zn(NO3)2 + 2 Ag

Once you have balanced the equation, you can use stoichiometry to convert the mass of silver nitrate (4.00 g) to the mass of zinc.

2.) If excess ammonium sulfate reacts with 22.5 g of calcium hydroxide according to the following unbalanced chemical equation:
(NH4)2SO4 + Ca(OH)2 → CaSO4 + NH3 + H2O

To solve this problem, you first need to balance the equation. After balancing the equation, you can use stoichiometry to convert the mass of calcium hydroxide (22.5 g) to the mass of ammonium sulfate.

If you have any further questions or need help with these calculations, feel free to ask!