1. FUNDAMENTAL CHEMICAL LAWS
- Lavoisier Law of Conservation of Mass
in a chemical reaction mass is neither created nor destroyed.
- Proust. Law of Definite Proportions
A given compound always contain exactly the same proportion of elements by weight.
- Dalton. Law of Multiple Proportions
When two elements form multiple compounds, the ratios of elemental masses can always be reduced to small whole numbers.
- Avogadro. Avogadro’s Hypothesis
At the same temperature and pressure, equal volumes of different gases contain the same number of particles.

2. مجموع جرم واكنش دهنده ها =مجموع جرم فراورده ها
قانون پايستگي جرم
- در يك واكنش شيميايي جرم نه به وجود مي آيد ونه از بين مي رود يا
در يك واكنش شيميايي:
مجموع جرم واكنش دهنده ها =مجموع جرم فراورده ها

3. قانون نسبتهاي معين

4. A sample of a compound composed of only carbon and hydrogen contains 79.89% carbon. Show that this compound obey the law of multiple proportions.
A g sample of calcium was burned, yielding g of a calcium-oxygen compound. How many grams of oxygen was taken up in the reaction?
If mg of a compound containing only carbon and hydrogen is burned completely in oxygen and yields mg of carbon dioxide and mg of water, how much oxygen is used up?

5. واكنش شيميايي
-- فرايندي است كه در آن حداقل يك ماده جديد به وسيله تغيير شيميايي ايجاد شود.
واكنش دهنده ها:
-- موادي كه قبل از شروع واكنش حضور دارند.(در طرف چپ نوشته مي شوند)
فراورده ها:
-- موادي كه در واكنش شيميايي توليد مي شوند.(در طرف راست نوشته مي شوند)

6. CHEMICAL EQUATION
-- a written statement using symbols and formulas to describe a chemical reaction.
or , it is
-- Chemist’s shorthand like
algebra to mathematicians
recipes to a chef
acronyms to the military
commuter jargon

7. Format:
1. Reactants on left, before reaction occurs.
2. Products on right, after reaction occurs.
3. Arrow points to products and means:
“goes to”, “produces”, “forms”,
“reacts to give”
4. + sign used between different reactants and
products.
Requirements:
1. Must be consistent with experimental facts.
2. Obeys conservation of mass.

8. Information conveyed by the Balanced Equation for the combustion of methane
واكنش دهنده ها  فراورده ها
CH4(g) + 2O2(g)  CO2 (g) + 2H2O(g)
1 مولكول CH  1 مولكول CO2
+ 2 مولكول O2 + 2 مولكول H2O
1 mol CH  1 mol CO2
+ 2 mol O2 + 2 mol H2O
6.022 x 1023 CH4 مولكول  x 1023 CO2 مولكول
+ 2(6.022 x 1023 ) O2 مولكول + 2(6.022 x 1023 ) H2O مولكول
16 g CH4 + 2(32 g)O  44 g CO2 + 2(18 g) H2O
80 g واكنش دهنده ها  80 g فراورده ها

9. نماد هاي مورد استفاده در واكنشهاي شيميايي
نماد معنا
 ”مي دهد“ يا ”توليد مي كند“
”تشكيل مي شود“
+ به علاوه“يا“و“ يا“واكنش مي دهد با“”
(s) جامد
(l) مايع
(g) گاز
(aq) محلول آبي

10. انواع واكنش هاي شيميايي
با تغيير در حالت اكسايش ويا بدون تغيير در حالت اكسايش
سوختن(احتراق)
CH4(g) + 2O2(g)  CO2 (g) + 2H2O(g)
سنتز(تركيب) A + X  AX
Fe(s) + S(s)  FeS(s)
تجزيه
AX  A X
2NaHCO3(s)  Na2CO3 (s) + H2CO3 (g) جابجايي يگانه(جايگزيني يگانه)
A + BX  B + AX or
Y + BX  BY + X
Fe(s) + CuSO (aq)  Cu(s) + FeSO4(aq)
جابجايي دوگانه
AX + BY  AY + BX
واكنشهاي رسوبي
واكنشهاي تشكيل گاز
هيدروليز
واكنشهاي خنثي شدن(اسيد و باز)
NaOH(aq) + HCl(aq)  NaCl(aq) + H2O(l)

11. DECOMPOSITION REACTIONS
(Au, Pt, Hg)
اكسيدهاي فلزهاي نوبل به عنصر هاي مربوطه تجزيه مي شوند.
2 Au2O3(s)    Au(s) + 3O2 (g)
هاليد هاي
PtCl4(s)  Pt(s) + 2Cl2 (g)
Peroxides decompose to oxides and oxygen gas
2H2O2(aq)  2H2O(l) + O2 (g)
Metal carbonates decompose to metal oxides and carbon dioxide gas; however, Group IA(I) metal carbonates do not decompose.
NiCO3(s)  NiO(s) + CO2(g)
Metal nitrates decompose to metal nitrites and oxygen gas if the metal is Al, and alkali metal, or an alkaline-earth metal; other metal nitrates decompose to metal oxides, nitrogen dioxide gas, and oxygen gas
2KNO3(s)  2KNO2(s) + O2(g)
2Zn(NO3)2(s)  2ZnO(s) + 4NO2(g) + O2 (g)
Oxoacids decompose to nonmetal oxides and water
H2SO3(aq)  SO2 (g) + H2O(l)

12. DECOMPOSITION REACTIONS
Oxoanion salts containing hydrogen ions decompose to oxoanion salts and oxoacids; the oxoacids may decompose further.
2NaHCO3(s)  Na2CO3 (s) + H2O(g) + CO2 (g)
Metal hydroxides decompose to metal oxides and water
Ca(OH)2(g)  CaO(s) + H2O(g)
Hydrates lose water to form an anhydrous salt.
CuSO4.5H2O(s)  CuSO4(s) + 5H2O(g)
Ammonium salts lose ammonia; if the salt contains an anion that is a strong oxidizing agent (such as nitrate, nitrite, or dichromate), oxidation-reduction produces an oxide, water, and nitrogen gas.
(NH4)2SO4(s)  2NH3 (g) + H2SO4(l)
(NH4) 2Cr2O7(s)  Cr2O3(s) + 4H2O(g) + N2(g)

13. BALANCING CHEMICAL EQUAITONS
A Balanced equation has an equal number of each element in reactants as in products.
Coefficients -- number of moles of a substance
Subscripts -- number of atoms of an element or
polyatomic ions in one mole of the
substance (compound)
coefficient – multiplier for H and O
2 H2O
subscript – multiplier for H only
coefficient – multiplier for Ca, P and O
3 Ca3(PO4)2
subscripts – 3 multiplier for Ca
- 4 multiplier for O
- 2 multiplier for both P & O

14. STEPS TO BALANCE AN EQUATION
Coefficients are the smallest set of whole numbers.
Consider polyatomic ions as single entities (use () to keep them together).
Subscripts in a compound may not be changed during balancing, only coefficients may be.
Product compounds of a reaction will be given or predicted from known principles.
Balancing “by inspection” is the method for this class. Certain reactions which involve changes in oxidation states require more detailed methods.
All chemical equations are the result of experimental data and may be verified by experiment.

15. Classify each of the following equations as balanced or unbalanced.
TiCl Ti  2TiCl3
SO2 + H2O  H2SO3
4NH O2  2N H2O
CS O2  CO2 + 2SO2

16. Balance the following equations.
N2 + O  NO
SO2 + O  SO3
U + F  UF6
Al + O  Al2O3
H2O  H2 + O2
Li + N  Li3N
Al + N  AlN
H2O + O  H2O2
C2H4 + O  CO2 + H2O
C3H6 + O  CO2 + H2O
C4H8 + O  CO2 + H2O
C5H O  CO2 + H2O

17. BALANCING CHEMICAL EQUATIONS
-- Determine the Reaction Occurring
- Reactants
- Products
- Physical States of Each
-- Write an Unbalanced Equation
-- Balance the Equation
- Start with the Most Complex Reactants
- Determine Coefficients Algebraically
- Do Not Change Any Compound Subscripts

18. Balance the following equations.
Ca(OH)2 + HNO3  Ca(NO3)2 + H2O
BaCl2 + (NH4)2SO4  BaSO4 + NH4Cl
Fe(OH)3 + H2SO4  Fe2(SO4)3 + H2O
Na3PO4 + AgNO3  NaNO3 + Ag3PO4
Al + Sn(NO3)2  Al(NO3)3 + Sn
Na2CO3 + Mg(NO3)2  MgCO3 + NaNO3
Al(NO3)3 + H2SO4  Al2 (SO4)3 + HNO3
Ba(C2H3O2)2 + (NH4)3PO4 
Ba3 (PO4)2 + NH4C2H3O2

19. Write balanced chemical equations to represent the reactions described by the following statements.
Steam (gaseous water) reacts with carbon at high temperatures to produce carbon monoxide (CO) and hydrogen gases.
Ethyl alcohol (C2H6O) burns in oxygen to produce carbon dioxide (CO2) and water.
Aluminum and sulfur react at elevated temperatures to produce aluminum sulfide (Al2S3)

20. Balance each of the following chemical equations:
C4H10(g) + O2(g)  CO2(g) + H2O(g)
C6H14(g) + O2(g)  CO2(g) + H2O(g)
B(s) + Cl2(g)  BCl3(l)
NO(g) + O2(g)  NO2(g)
Ti2O3(s) + CO2(g)  Ti2(CO3)3(s)
OF2(g)  O2(g) + F2(g)
NaClO3(s)  NaCl(s) + O2(g)
Al(OH)3(s)  Al2O3(g) + H2O(l)

21. Balance each of the following chemical equations
Br2(l) + KI(aq)  KBr(aq) + I2(s)
Co(s) + O2  Co2O3(s)
P4(s) + O2(g)  P4O10(s)
Al(s) + HNO3(aq)  Al(NO3)3(aq) + H2(g)
PBr3(l) + H2O(l)  H3PO3(aq) + HBr(aq)
NO(g) + O2(g)  NO2(g)
C2H6(g) + O2(g)  CO2(g) + H2O(g)
CuO(s) + H2SO4(aq)  CuSO4(aq) + H2O(l)

22. STOICHIOMETRY
Stoichiometry is the relationship of quantities of reactants consumed and products made in a chemical reaction.
Mole
A mole is the number of atoms in exactly 12 grams of carbon 12.
One mole of any substance contains x 1023 atoms (Avogadro’s number) of that substance.
The mass of one mole of an element is the weighted average atomic mass of that element OR the total of all the element masses in a compound or chemical formula.

23. Calculations Based on Chemical Equations - Stoichiometry
Avogadro’s
formula
Avogadro’s
Moles
Of A
Moles
Of B
Particles
Of A
Particles
Of B
number
subscript
number
molar
mass
molar
mass
Grams
Of A
Grams
Of B
Chemical stoichiometry is the study of the quantitative relationships among reactants and products in a chemical reaction.

24. EQUATIONS and the MOLE CONCEPT
Moles of equation moles of

Substance A coefficients substance B
Coefficients give the numerical relationships among formula units consumed and/or produced in a chemical reaction.
P4O H2O  4 H3PO4
3 mole to mole relations:
1 mole P4O10 produces 4 moles of H3PO4
6 mole H2O produces 4 moles of H3PO4
1 mole of P4O10 produces 6 moles of H2O
Now write dimensional analysis factors:
1 mole P4O10 and moles H3PO4
 
4 moles H3PO mole P4O10 OR ?

25. Give a word interpretation of the balanced equation
a. 4 NH O2  2 N H2O
b CS O2  CO SO2
in terms of (a) molecules and (b) moles
Write the twelve mole-to-mole conversion factors that can be derived from the balanced equation
a. 3 HNO2  2 NO + HNO3 + H2O
b N2H H2O2  N H2O

26. How many moles of the first-listed product in each of the following equations could be obtained by reacting mole of the first-listed reactant with an excess of the other reactant?
H2O2 + H2S  2H2O + S
4NH O2  2N H2O
Mg + 2HCl  MgCl2 + H2
6HCl + 2Al  3H AlCl3
SiO C  2CO + SiC
5O2 + C3H8  3CO2 + 4H2O
CH Cl2  4HCl + CCl4
3NO2 + H2O  2HNO3 + NO

27. Given the equation
4NH3(g) + 5O2(g)  4NO(g) + 6H2O(g)
How many moles of O2 are needed to produce 1.34 moles of NO?
How many moles of H2O will be produced from mole of NH3?
How many moles of NH3 are needed to react with 3.22 moles of O2?
How many moles of NO are produced when mole of H2O is produced?

28. Given the equation
C3H8(g) + 5O2(g)  3CO2(g) + 4H2O(g)
How many moles of O2 are needed to produce 2.38 moles of H2O?
How many moles of CO2 will be produced form 0.57 mole of C3H8?
How many moles of C3H8 are needed to react with 1.45 moles of O2?
How many moles of CO2 are produced when 1.11 moles of H2O are produced?

29. STOICHIOMETRIC CALCULATIONS of Masses/Moles
Use Dimensional Analysis
Balance the reaction equation
Convert known masses to moles
Set up mole ratios from the equation
Calculate Moles of desired product or reactant
Convert from moles to mass as required

30. One way to remove gaseous carbon dioxide (CO2) form the air in a spacecraft is to let canisters of solid lithium hydroxide (LiOH) absorb it according to the reaction.
CO2(g) + 2LiOH(s)  Li2CO3(s) + H2O(l)
a. How many grams of LiOH are needed to react
with moles of CO2?
b. How many grams of H2O are obtained when
2.50 moles of CO2 react?
c. How many grams of Li2CO3 are produced when
0.500 mole of H2O is produced?
d. How many grams of LiOH must react in order
to produce 12.0 moles of Li2CO3?

31. How many grams of the first reactant in each of the following equations would be needed to produce 2.00 g of O2?
a. OF2 + H2O  O2 + 2HF
b. 2Na2O CO2  2Na2CO3 + O2
c. 4C3H5O9N3  12CO2 + 6N2 + O H2O
d. 2ClO2 + Na2O2  2NaClO2 + O2

32. How many grams of the first reactant in each of the following equations would be needed to produce 3.00 g of O2?
a. 4NH O2  2N H2O
b. (NH4)2Cr2O7  Cr2O3 + N H2O
c. N2H H2O2  N H2O
d. 4C3H5O9N3  12CO N2 + O H2O

33. Pure silver metal results when silver carbonate (Ag2CO3) is decomposed by heating as shown by the equation
2Ag2CO3  4Ag + 2CO2 + O2
Based on this equation, how many grams of Ag2CO3 must be decomposed to produce each of the following?
a moles of O2
b. 1 billion (1.00 x 109) molecules of CO2
c g of O2
d. 115,000 atoms of Ag

34. A common method for producing lime (CaO) is the thermal decomposition of limestone (CaCO3)
CaCO3  CaO + CO2
Based on this equation, how many grams of CaCO3 must be decomposed to produce each of the following?
a moles of CO2
b x 1020 molecules of CO2
c g of CaO
d formula units of CaO

35. THE LIMITING REACTANT CONCEPT
The limiting reactant is the reactant in a chemical reaction that determines how much product(s) can be formed
An assembled
Handout
experiment
Title page
Data sheets
Graph paper
Instructions
4 sheets
Of graph
paper
2 data sheets
1 sheet
Of instructions
20 copies
21 copies
1 title page
40 copies
(2 X 20)
76 copies
(4 X 19)

36. LIMITING REACTANTS STOICHIOMETRIC CALCULATIONS of Masses/ Moles
Use Dimensional Analysis
Balance the reaction equation
Convert known masses to moles
Determine the limiting Reactant
Set up mole ratios from the equation
Calculate Moles of desired product or reactant
Convert from moles to mass as required

37. Grams of First reactant, A Grams of Second reactant, B
Molar mass
Molar mass
Moles of A
Moles of B
Compare ratio of moles of A present to moles of B present
With mole ratio from balanced chemical equation
Balanced chemical equation
Using limiting reagent
Moles of Product
Molar mass
Grams of product

38. Using each o f the following equations, calculate the number of moles of the first-listed reactant that are needed to produce 4.00 moles of CO2
a. 3O2 + CS2  CO SO2
b. FeO + CO  Fe + CO2
c. 2C8H O2  16CO H2O
d. Fe3O4 + CO  3FeO + CO2

39. Using each o f the following equations, calculate the number of moles of the first-listed reactant that are needed to produce 3.00 moles of CO2
a. C7H O2  7CO H2O
b. 2HCl + CaCO3  CaCl2 + CO2 + H2O
c. Na2SO C  Na2S + 2CO2
d. 4Na2CO3 + Fe3Br8  8NaBr + 4CO Fe3O4

40. Limiting Reactant:
Magnesium nitride can be prepared by the direct reaction of the elements as shown by the equation.
3Mg + N2  Mg3N2
For each of the following combinations of reactants, decide which is the limiting reagent.
a moles of Mg and moles of N2
b moles of Mg and 1.25 moles of N2
c g of Mg and moles of N2
d g of Mg and 7.00 g of N2

41. Under appropriate conditions water can be produced form the reaction of the elements hydrogen and oxygen as shown by the equation
2H2 + O2  2H2O
For each of the following combinations of reactants decide which is the limiting reactant.
a moles of H2 and 1.00 mole of O2
b moles of H2 and 2.00 moles of O2
c g of H2 and 1.25 moles of O2

42. How many grams of ZnCl2 can be produced form the reaction of 10
How many grams of ZnCl2 can be produced form the reaction of 10.0 g of Zn and 10.0 g of HCl according to the following reaction?
Zn + 2HCl  ZnCl2 + H2
Determine the number of grams of each of the products that can be made form 8.00 g of SCl2 and 4.00 g of NaF by the reaction.
3SCl NaF  SF4 + S2Cl NaCl

43. For the balanced reaction below, answer the following questions:
H2O H2S  2H2O + S
1. How many moles of water are produced from moles of H2S?
a b. 1 c. 2 d. 2.5
2. What is the % yield if only 31 grams of S is
produced from reacting 34 grams of H2S with an excess of H2O2?
a b. 91 c. 49 d. 97
3. How many grams of CO can be produced from the reaction of 10.0 grams of ZnO and grams of C according to the following balanced equation? Show all Work
ZnO(s) + C(s)  Zn(s) + CO(g)

44. SIMULTANEOUS AND CONSECUTIVE REACTIONS
When two or more reactions are involved in stoichiometric calculations, each molar relationship must be taken into account.
Example:
In steel making, a three step process leads to conversion of Fe2O3 into metallic Fe.
3Fe2O3 + CO  2Fe3O4 + CO2
Fe3O4 + CO  3FeO + CO2
FeO + CO  Fe + CO2
How many grams of Fe are produced from grams of Fe2O3?
WANT = HAVE X CONVERSIONS

45. WANT = HAVE X CONVERSION FACTORS

46. Determine the number of grams of each of the products that can be made from 8.0 grams of SCl2 and 4.00 grams of NaF by the reaction.
3SCl NaF  SF4 + S2Cl NaCl

47. In steelmaking, a three-step process leads to conversion of Fe2O3 into metallic Fe.
3 Fe2O CO  2 Fe3O4 + CO2
Fe3O4 + CO  3 FeO + CO2
FeO + CO  Fe + CO2
How many grams Fe are produced from grams of Fe2O3?

48. Simultaneous reactions
A mixture of composition 60% ZnS and 40% CuS is heated in air until the sulfides are completely converted to oxides as shown by the following equations.
2ZnS + 3O2  2ZnO + 2SO2
2CuS + 3O2  2CuO + 2SO2
How many grams of SO2 are produced from reaction of 82.5 g of the sulfide mixture?

49. Simultaneous reactions
A mixture of composition 50.0% H2S and 50.0% CH4 is reacted with oxygen, producing SO2, CO2 and H2O. The equations for the reactions are
2H2S + 3O2  2SO H2O
CH O2  CO H2O
How many grams of H2O are produced from the reaction of 65.0 g of mixture?

50. Consecutive Reactions
How many grams of SO2 can be obtained form 50.0 g of KClO3 by the following two-step chemical process?
2KClO3  2KCl + 3O2
S + O2  SO2
NO2 is a reddish brown gas that is a component of smog. It is formed in the following two-step process.
N2 + O2  2NO
2NO + O2  2NO2
How many grams of NO2 result from the reaction of 2.00 g of N2?

51. PRODUCT YIELD
THEORETICAL YIELD is the maximum amount of products from the reactants.
ACTUAL YIELD is the amount of product achieved in the experiment
low% yield: side reactions
product lost
high % yield: product contamination, e.g. water

52. Theoretical and Percent Yield
Because of “sloppiness” in his procedures, a student was able to isolate only 16.0 g of a desired product from a chemical reaction rather than the 52.0 g that was theoretically possible. What was the percent yield of product that the student obtained?
The theoretical yield of product for a particular reaction is g. A very “meticulous” student isolates g of product when the reaction is run. What is the percent yield that this student obtained?

53. Theoretical and Percent Yield
Aluminum and sulfur react at elevated temperatures to form aluminum sulfide as shown by the equation.
2Al + 3S  Al2S3
In a certain experiment, 125 g of Al2S3 was produced from 75.0 g of Al and g of S.
a. What is the theoretical yield of Al2S3
b. What is the percent yield of Al2S3
5.000 g of Ag2S was produced form g of Ag and an excess of S according to the reaction
2 Ag + S  Ag2S
What is the percent yield of Ag2S?