1. Reaction Stoichiometry

2. Chemical reactions and equations Reactants Products

3. Chemical reactions and equations Reactants Products
CH3CHCH2 + HCl
CH3CHClCH3

4. The most important thing: It’s the same atoms Reactants Products
CH3CHCH2 + HCl
CH3CHClCH3

5. Chemical equation: before and after Mechanism: how you get there
Step 1.
Step 2.

6. Balancing Equations:
Use models
CH3OH + O2

7. Balancing Equations:
CH3CH2OH O CO H2O

8. Balancing Equations: North Korean Rocket Fuel
(CH­3)2NNH2(l) + N2O4(g) N2(g) + H2O(g) + CO2(g)

9. Reaction Stoichiometry
Grams
reactant
Moles
reactant
Moles
product
Grams
product
CH3CH2OH O CO H2O
Balanced Equation gives mol-mol conversion factors.

10. Pb(NO3)2(aq) + 2 NaCl(aq)  PbCl2(s) + 2 NaNO3(aq) If you have 5
Pb(NO3)2(aq) + 2 NaCl(aq)  PbCl2(s) + 2 NaNO3(aq)   If you have 5.00 moles of Pb(NO3)2, how many moles of PbCl2 can you make? How many moles of NaNO3 can you make?

11. If we react 115 g CH3CH2OH, what mass of H2O is formed?
CH3CH2OH O CO H2O

12. Fuel Comparison: C + O2 CO2 CH4 + O2 CO2 + H2O CH3CH2OH + O2 CO2 + H2O
Determine the mass of CO2 formed
from burning 1.00 kg C, CH4 and CH3CH2OH
C O CO2
CH O CO H2O
CH3CH2OH O CO H2O

13. C O CO2

14. CH O CO H2O

15. Theoretical Yield and Percent Yield
2 Al(s) + 2 KOH(aq) + 4 H2SO4(aq) + 22 H2O(l)  2 KAl(SO4)2 12H2O(s) + 3 H2(g)
Calculation of Theoretical Yield: Map: grams reactant  moles reactant  moles product  grams product
If you react g Al, what mass of alum (KAl(SO4)2 12H2O(s)) is theoretically possible to form?
1.083 g Al × 1 mol Al g Al = mol Al
mol Al × 1 mol alum 1 mol Al = mol alum
mol alum × g alum 1 mol alum = 19.0 g KAl(S O 4 ) 2 °12 H 2 O
This is the “theoretical yield.”

16. Calculation of Percent Yield:
If you do the reaction using g Al and obtain 15.2 g KAl(SO4)2 12H2O(s), what is the percent yield?
Percent Yield = Actual Yield (g) Theoretical Yield (g) × 100%

17. What would cause the yield to be less than 100%
What would cause the yield to be greater than 100%?

18. Using Amounts Tables:
If we react 132 grams of CH3CH2OH, how many grams of H2O are formed,
how many grams of O2 react?
CH3CH2OH O2  CO H2O

20. Limiting Reactants
1. If you have 200 tires and 75 steering wheels, how many cars can you make?
1. 200
2. 75
3. 50
4. 100

21. A cake recipe calls for 3 eggs, 2 cups of flour, and 3 teaspoons of sugar. If you have:
How many cakes can you make?

23. 2 CO(g) + O2(g)  2 CO2(g)
If you start with 4 CO molecules and 3 O2 molecules, which mixture will result?

24. Determining the Limiting Reactant: If you have 5 P4 molecules and 20 Cl2 molecules, which will run out first? P4 + 6 Cl2  4 PCl3

25. Limiting Reactants Simulation
Course Website
Simulations
Chapter 3/Limiting Reactants

26. Reaction to make iron (steel) from iron ore:
If you react 496 g Fe with 122 g C, which is the limiting reactant? What amount of Fe can be produced? What mass of reactant in excess remains?
2 Fe2O C  Fe CO2

27. KEY: amounts reacted and formed determined from the limiting reactant.
Amounts Table:
2 Fe2O C  Fe CO2

28. KEY: amounts reacted and formed determined from the limiting reactant.
Amounts Table:
2 Fe2O C  Fe CO2

29. Amounts Tables
2 CO(g) + O2(g)  2 CO2(g)
Initial
Change
Final

30. A hard somewhat MindTap Question
14.3 g CO react with 6.48 g H2O to form H2 and CO2.
What are the masses of all species following the reaction?

31. Chemical Analysis: Use mass measurements to figure stuff out.

32. A 5.486 gram sample of a compound containing C, H and O is analyzed by combustion analysis and 9.136 grams of CO2 and 2.993 grams of H2O are produced. What is the empirical formula? 

33. A 5.486 gram sample of a compound containing C, H and O is analyzed by combustion analysis and 9.136 grams of CO2 and 2.993 grams of H2O are produced. What is the empirical formula? 

34. A 5.486 gram sample of a compound containing C, H and O is analyzed by combustion analysis and 9.136 grams of CO2 and 2.993 grams of H2O are produced. What is the empirical formula? 

35. Chemical Analysis A gram sample of manganese is heated in the presence of excess sulfur. A metal sulfide is formed with a mass of g. Determine the empirical formula of the metal sulfide.

37. A sample of a substance with the empirical formula XCl2 weighs 0
A sample of a substance with the empirical formula XCl2 weighs g. When it is dissolved in water and reacted with AgNO3, all its chlorine is converted to insoluble AgCl. The mass of the resulting AgCl is found to be g. The chemical reaction is XCl2 + 2 AgNO3  2 AgCl + X(NO3) X is an unknown element (a) Calculate the formula mass of XCl2. molar mass XCl2 = _____ g mol-1 (b) Calculate the molar mass of X. Atomic mass X = g mol-1