Stoichiometry help!

This is not a test! I’m not cheating 🙂 but I’m so lost! I don’t like asking for help because my parents get mad and tell me to figure it out myself. But I could really use some help please! I only need five out of twenty. Could you explain as well as answer? Thanks!

 

 

3. When carbon dioxide dissolves in water, carbonic acid H2CO3 is formed. When this enters limestone (CaCO3), it dissolves the limestone, sometimes producing caves. It 804 kg of calcium hydrogen carbonate is formed, how many kg of limestone were dissolved?

CaCO3 (s) + H2CO (aq) -> Ca(HCO3)2 (aq)

 

8. Hydrogen and nitrogen react to form ammonia (NH3). Write the balanced equation and determine how many moles of nitrogen are needed to react with 8.37 moles of hydrogen.

 

14. Calculate which reactant is limiting if 25.0g of chlorine reacts with 16.0g of phosphorus (P2) to produce phosphorus tetra chloride (PCI4).

 

17. Calculate the theoretical and percent yields if 934 grams of sucrose (C12H22O11) react and 493 grams of ethanol (C2H5OH) are actually produced. The fermentation of sucrose is: C12H22O11 + H2O -> 4CO2 + 4 C2H5OH

 

19. Sulfuric acid (H2SO4) is produced from water vapor, sulfur dioxide, and oxygen gas. Write a balanced equation, then determine how many grams of sulfuric acid can be produced if 916.0 grams of water react. 

–and there’s a bonus for question 19 I don’t get. I don’t necessarily need the answer, but if you wanna be nice you can answer it 🙂 —

Determine the actual yield if the percent yield is 91.2%.