1. Intro to Reactions Ch 11 honors Ch 8 cp chem
Chemical Reactions
Intro to Reactions Ch 11 honors Ch 8 cp chem

2. During your life you have witnessed numerous chemical reactions.
What were some of those reactions?
How did you know that a reaction was going on?
How would you describe them to someone else?

3. What do you see in this picture?

4. A.Signs of a Chemical Reaction
Evolution of heat and light
Formation of a gas
Formation of a precipitate
Color change

5. B.Law of Conservation of Mass
mass is neither created nor destroyed in a chemical reaction
total mass stays the same
atoms can only rearrange
4 H
2 O
4 H
2 O
36 g
4 g
32 g

6. C. Chemical Equations
A+B  C+D
REACTANTS
PRODUCTS

7. C. Chemical Equations
p. 246

8. Diatomic Molecules Elements that cannot appear by themselves
Will always appear in pairs bonded to themselves
Br2, I2, N2, Cl2, H2, O2, F2

9. 2H2(g) + O2(g)  2H2O(g) D. Writing Equations
Identify the substances involved.
Use symbols to show:
How many? - coefficient
Of what? - chemical formula
In what state? - physical state
Remember the diatomic elements.

10. D. Writing Equations 2 Al (s) + 3 CuCl2 (aq)  3 Cu (s) + 2 AlCl3 (aq)
Two atoms of aluminum react with three units of aqueous copper(II) chloride to produce three atoms of copper and two units of aqueous aluminum chloride.
How many?
Of what?
In what state? 2 Al
(s)
+ 3
CuCl2
(aq)
 3 Cu
(s)
+ 2
AlCl3
(aq)

11. E. Describing Equations
Describing Coefficients:
individual atom = “atom”
covalent substance = “molecule”
ionic substance = “unit”
3CO2 
2Mg 
4MgO 
3 molecules of carbon dioxide
2 atoms of magnesium
4 units of magnesium oxide

12. E. Describing Equations
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
How many?
Of what?
In what state?
One atom of solid zinc
reacts with
two molecules of aqueous hydrochloric acid
to produce
one unit
of aqueous zinc chloride
and one
molecule of hydrogen gas.

13. Which of the following involves a chemical change
Which of the following involves a chemical change? What evidence supports your choice?
The burning of gasoline
The freezing of water
Magnesium burning in oxygen to form magnesium oxide
Methane melting at -182C
Boiling of an egg
Liquid solutions of potassium chloride plus silver nitrate combining to form solid silver chloride
Nitroglycerine exploding on impact or when heated
Water boiling at 100C
Not all the items are examples of a chemical change. What kind of change are they?

14. Internet activity – introducing reactions

15. End of day 1 notes Honors homework: Read section 11.1
Do the reading strategy from page 321
Page 329 #s 7,8, & 9
Extra credit practice problems 1-6
CP Chem homework: read section 8-1

16. 5. Chemical Reactions and Stoichiometry
Central Concepts: In a chemical reaction, one or more reactants are transformed into one or more new products. Chemical equations represent the reaction and must be balanced. The conservation of atoms in a chemical reaction leads to the ability to calculate the amount of products formed and reactants used (stoichiometry).

17. 5.1 Balance chemical equations by applying the laws of conservation of mass and constant composition (definite proportions).
5.2 Classify chemical reactions as synthesis (combination), decomposition, single displacement (replacement), double displacement, and combustion.
5.3 Use the mole concept to determine number of particles and molar mass for elements and compounds.
5.4 Determine percent compositions, empirical formulas, and molecular formulas.
5.5 Calculate the mass-to-mass stoichiometry for a chemical reaction.
5.6 Calculate percent yield in a chemical reaction.