The student will learn:
How to read/write balance chemical equations
Identify 6 types of reactions
interpret signs of written reactions
determine physical or chemical changes
to reason if a reaction took place
Balancing Chemical Equations
Understanding ratio of atoms in a compound
Count the number of each element in each compound:
H 2O
4 LiOH
3 Na2SO4
5 Mg(OH)2
6 H2SO3
9 CuCl2
7 SO2
Coefficient
subscript
Law of Conservation of Mass/Matter
“matter can neither be created nor destroyed”
50 lbs of stuff here
50lbs of stuff over here
To properly satisfy the law of conservation of mass we must
write balanced chemical equations.
Pb(NO3)2 + KI
l.
2.
3.
4.
5.
Write Correct Chemical Formulas
Must have same number of atoms on each side
May not change subscripts
“Strictly trial & error”
“when I get stuck I start over with the hard one”
ws. 8.1, 8.2
Balance Equations ws 8.1
1. Fe + AgNO3
2. AgI + Fe2(CO3)3
3. C2H4 + O2
4. S8 + O2
5. H2SO4 + NaNO3
Fe(NO3)2 + Ag
FeI3 + Ag2CO3
CO2 + H2O
SO2
HNO3 + Na2SO4
• 6. NaNO3 + PbO
• 7. H2O +
• 8. P4 +
• 9. Na +
O2
H2O2
O2
P2O5
H2O
• 10. FeCl3 +
Pb(NO3)2 + Na2O
NaOH
NaOH + H2
Fe(OH)3 +
NaCl
• ll. C2H6 +
O2
• 12. KNO3
• 13. VF5 +
• 14. C +
• 15. C6H6 +
CO2 + H20
KNO2 + O2
HI
H2
V2I10 + HF
C3H8
O2
CO2 + H2O
Ws.8.2 Balancing Equations from Word Equations
Pure elements are written with their symbols.
Copper bar ….. Cu
Zinc was added …. Zn
Exceptions are …. S8 …. P4
Diatomics: N2, O2, F2, Cl2, Br2, I2, H2
Aluminum and hydrochloric acid react to form aluminum chloride and hydrogen
Calcium hydroxide and phosphoric acid react to form calcium phosphate and
water.
Word equations 8.2
1. Aluminum bromide and chlorine gas react to form
aluminum chloride and bromine gas.
2. Sodium Phosphate and calcium chloride react to form
calcium phosphate and sodium chloride.
3. Copper and sulfuric acid react to form copper II sulfate
and water and sulfur dioxide.
4. Zinc and Lead II nitrate react to form Zinc Nitrate and Lead.
5. Hydrogen gas and nitrogen monoxide react to form water
and nitrogen gas.
6. Aluminum sulfate and barium chloride react to form
aluminum chloride and barium sulfate.
7. Calcium carbonate decomposes to form calcium oxide and
carbon dioxide gas.
8. Potassium chloride and silver nitrate react to form
potassium nitrate and silver chloride.
9. Diphosphorus pentoxide and water react to form
phosphoric acid.
10. Nitrogen and hydrogen react to form ammonia
11. Aluminum Sulfate and phosphoric acid react to form
aluminum phosphate and sulfuric acid
12. Baking Soda decomposes to sodium carbonate and
carbon dioxide and water
Chemical Changes = Chemical Reactions
Chemicals
Reactants
Chemicals
Products
Symbols for reactions
Gas
Heat
liquid
catalyst
solid
precipitant
in water solution
yield
conditions
How you can you tell there is a chemical reaction?
How do you describe it?
Physical Properties
Observed or measured w/o
changing the substance
“describes it”
Melting point
Boiling point
Color, odor, taste, hardness,
malleable, ductile
Chemical Properties
Relates to the ability to transform into a
different substance
“Does it make a new substance with new
properties”
Burning
Rusting
Tarnish
Reaction w/ acids
w/ bases
w/ H2O
Physical Change
A change in substance that does not
involve a change in identify
Grinding
Cutting* paper
Melting
boiling
Chemical Change
“reaction happens and produces
new substance with new
properties”
Burning*
paper
“evidence of a chemical reaction…
evolved heat,
color change,
precipitant,
gas given off
6 Types of Reactions
1.
2.
3.
4.
5.
6.
Decomposition
Synthesis
Single Replacement
Double replacement
Acid-Base Neutralization
Combustion