1. in the Equation Above, 2 Molecules React with ____ Molecules of O2 to Produce

REVIEW Ch 12

2 H2S (g) + 3 O2 (g)  2 SO2 (g) + 2 H2O (g)

1. In the equation above, 2 molecules react with ____ molecules of O2 to produce ____molecules of sulfur dioxide and ____molecules of water. OR you could say that ___Liters of hydrogen sulfide gas react with ____ L of oxygen gas to produce ____L of ______and ___L of ______OR you could say when 2 moles of hydrogen sulfide react with ___ moles of ______sulfur dioxide forms along with ___moles of water containing ______molecules H2O

2. What interpretations similar to those above could you make for this equation?

2 Na (s) + 2 H2O (l)  2 NaOH (aq) + H2 (g)

Mole-Mole Calculations

4Al + 3O2  2Al2O3 3. How many moles of Al are needed to form 2.3 mol of Al2O3?

4. How many moles of O2 are required to react completely with 0.84 mol of Al?

5. Calculate the number of moles of Al2O3 formed when 17.2 mol of O2 react with Al.

Mass-Mass Calculations

N2 (g) + 3H2 (g)  2NH3 (g)

6. Calculate the grams of NH3 produced by the reaction of 5.40 grams of H2 with excess N2

7. How many grams of nitrogen are needed to produce 30.6 grams of ammonia?

Mixed Stoichiometry Calculations electricity 2 H2O (l)  2 H2 (g) + O2 (g)

8. How many liters of oxygen are produced @STP when 29.2 grams of water is decomposed?

9. How many liters of hydrogen are produced when 29.2 grams of water is decomposed?

2 SO2 (g) + O2 (g)  2 SO3

10. Assuming STP, how many liters of oxygen are needed to produce 19.8 L of SO3?

11. How many grams of SO3(g) are formed if 8.45 L of oxygen are used? 12. How many molecules of oxygen are used to form 160.14 g of sulfur trioxide?

Limiting Reagent

2 Na (s) + Cl2 (g)  2 NaCl (s)

6.70 mol of Na reacts with 3.20 mol of Cl2 13. What is the limiting reagent?

14. How many moles of NaCl are produced?

Mg (s) + 2HCl (aq)  MgCl2 (aq) + H2

15. How many grams of H2 can be produced when 4.00 g of HCl is added to 3.00 g of Mg?

16. Assuming STP, what is the volume of the hydrogen when 4.00 g of HCl is added to 3.00 g of Mg?

Percent Yield (You must show all work for stoichiometry as well as the percent yield)

17. Fe2O3 + 3CO  2Fe + 3CO2 What is the percent yield when 84.8 g of Fe2O3 reacts with an excess of CO and actually yields 57.8 g of Fe ?

D 18. SiO2 + 3C 揪 SiC + 2CO

What is the percent yield of silicon carbide when 50.0 g of SiO2 is heated with an excess of C and yields 32.2 g of SiC?

Questions 19. How much does one mole of an element weigh? 20. What is the mass of one mole of a compound? 21. How much space does one mole of a gas occupy? 22. What is the volume of one mole of a liquid? 23. How many molecules does it take to make a mole? 24. What is a limiting reagent? 25. What is theoretical yield? Where do you get it? Can it be affected by sloppy lab technique? 26. How does actual yield differ from theoretical? Which is usually larger? 27. Should you use the coefficients when figuring molar mass? Should you use the subscripts?