Chemistry Equations

[waltz]

I am a student in the ninth grade and I need help with the following problems because I do not understand how to do them. I appreciate your help and thanks once again.

7. in 2CO(grams) + O₂(grams) => 2CO₂(grams), what is the ratio of moles of oxygen used to moles of CO₂?

9. when iron rusts in air, iron(III) oxide is produced. how many moles react with 2.4 iron in the rusting reaction? 4Fe(s) + 3O₂(g) => 2Fe₂O₃(s)

22. iron (III) oxide is formed when iron combines with oxygen in the air. how many grams of Fe₂O₃ are formed when 16.7g of Fe reacts completely with oxygen? 4Fe(s) + 3O₂(grams) => 2Fe₂O₃(s)

23. aluminum reacts with sulfuric acid to produce aluminum sulfate and hydrogen gas. how many grams of aluminum sulfate would be formed if 250g H₂SO₄ reacted with aluminum?

24. how many liters of chlorine gas can be produced when .98L of HCl react with excess O at STP? 4HCl(g) + O₂(g) => 2Cl(g) + 2H₂O(g)

27. which would be the limiting reagent in the reaction: 2H₂(g) + O₂(g) => 2H₂O(g)

a. 50 molecules of H₂
b. 50 molecules of O₂

31. at STP, how many liters of oxygen are required to react completely with 3.6 liters of hydrogen to form water? 2H(g)+ O₂(g) => 2H₂O(g)

37. if 8.6L of H₂ reacted with 4.3L of O₂ at STP, what is the volume of gaseous water collected (assuming none of it condenses)? 2H₂(g) + O₂(g) => 2H₂O(g)

38. how many liters of O₂ are needed to react completely with 45L of H₂S at STP? 2H₂S(g) + 3O₂(g) => 2SO₂(g) + 2H₂O(g)

39. for the reaction 2Na(s) + Cl₂(g) => 2NaCl(s), how many grams of NaCl could be produced from 103g of Na and 13L of Cl₂ (at STP)?

46. how many grams of CO are needed to react with an excess of Fe₂O₃ to produce 209.7gFe? Fe₂O₃(s) + 3CO(g) => 3CO₂(g) + 2Fe(s)