3 stoichiometry questions

39.6 g of Zn reacts with 96.9 g of Br to produce
ZnBr2, the only product, with no reactant left
over. How much Zn would be needed to react
with 121 g Br to produce ZnBr2?

1. 171 g
2. 0.0201 g
3. 0.00337 g
4. 297 g
5. 418 g
6. 0.0284 g
7. 49.7 g
8. 35.3 g
9. 86.2 g
10. 0.00584 g

--------------------------------------…

When limestone (which is principally CaCO3) is heated, carbon dioxide and quicklime (CaO) are produced by the reaction

CaCO3(s) -- ^ --> CaO(s) + CO2(g) .

If 15.5 g of CO2 was produced from the thermal decomposition of 38.73 g of CaCO3, what is the percentage yield of the reaction?
Answer in units of %.

-------------------------------------

What mass of sulfur must be used to produce 26.3 L of gaseous sulfur dioxide at STP according to the following equation?

S8 (s) + 8O2 (g) --> 8 SO2 (g)

Answer in units of g.

Hey, it's Milan, the guy helping everyone with Quest, essentially. These are the answers you're looking for:

First Question: 7.) 49.7 g
Second Question: 91.01721066%
Third Question: 37.65361307 g

I sincerely hope this is of help to you!