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 2 O 4 LiOH 3 Na 2 SO 4 5 Mg(OH) 2 6 H 2 SO 3 9 CuCl 2 7 SO 2 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(NO 3 ) 2 + KI l.Write Correct Chemical Formulas 2.Must have same number of atoms on each side 3.May not change subscripts 4.“Strictly trial & error” 5.“when I get stuck I start over with the hard one” ws. 8.1, 8.2

Balance Equations ws Fe + AgNO 3 Fe(NO 3 ) 2 + Ag 2. AgI + Fe 2 (CO 3 ) 3 FeI 3 + Ag 2 CO 3 3. C 2 H 4 + O 2 CO 2 + H 2 O 4.S 8 + O 2 SO 2 5.H 2 SO 4 + NaNO 3 HNO 3 + Na 2 SO 4

6. NaNO 3 + PbOPb(NO 3 ) 2 + Na 2 O 7. H 2 O + O 2 H 2 O 2 8. P 4 + O 2 P 2 O 5 9. Na + H 2 ONaOH + H FeCl 3 + NaOHFe(OH) 3 + NaCl

ll. C 2 H 6 + O 2 CO 2 + H KNO 3 KNO 2 + O VF 5 + HIV 2 I 10 + HF 14. C + H 2 C 3 H C 6 H 6 + O 2 CO 2 + H 2 O

Ws.8.2 Balancing Equations from Word Equations Pure elements are written with their symbols. Copper bar ….. Cu Zinc was added …. Zn Exceptions are …. S 8 …. P 4 Diatomics: N 2, O 2, F 2, Cl 2, Br 2, I 2, H 2 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 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 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/ H 2 O

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.Decomposition 2.Synthesis 3.Single Replacement 4.Double replacement 5.Acid-Base Neutralization 6.Combustion