The student will learn:

How to read/write balance chemical equations

Identify 6 types of reactions

interpret signs of written reactionsdetermine physical or chemical changes

to reason if a reaction took place

Balancing Chemical Equations

Understanding ratio of atoms in a compoundCount the number of each element in each compound:

H2O4 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. Write Correct Chemical Formulas2. Must have same number of atoms on each side 3. May not change subscripts4. “Strictly trial & error”5. “when I get stuck I start over with the hard one”

ws. 8.1, 8.2

Balance Equations ws 8.1

1. Fe + AgNO3 Fe(NO3)2 + Ag

2. AgI + Fe2(CO3)3 FeI3 + Ag2CO3

3. C2H4 + O2 CO2 + H2O

4. S8 + O2 SO2

5. H2SO4 + NaNO3 HNO3 + Na2SO4

• 6. NaNO3 + PbO Pb(NO3)2 + Na2O

• 7. H2O + O2 H2O2

• 8. P4 + O2 P2O5

• 9. Na + H2O NaOH + H2

• 10. FeCl3 + NaOH Fe(OH)3 + NaCl

• ll. C2H6 + O2 CO2 + H20

• 12. KNO3 KNO2 + O2

• 13. VF5 + HI V2I10 + HF

• 14. C + H2 C3H8

• 15. C6H6 + 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 8.21. 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 ChemicalsReactants Products

Symbols for reactions

Gas liquid solid precipitant yield

Heat catalyst in water solution 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

GrindingCutting* paper

Meltingboiling

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. Decomposition

2. Synthesis

3. Single Replacement

4. Double replacement

5. Acid-Base Neutralization

6. Combustion