1. Chemical reactions
Chapter 13.2

2. Standards:
GLE
Distinguish among elements, compounds, and mixtures.
GLE
Interpret the events represented by a chemical equation

3. Key concepts: Interpret and write simple chemical formulas
Identify the reactants and products of a chemical reaction.

4. Key Vocabulary:
Chemical formula
Chemical equation
Reactant
Product

5. What do you already know?
Imagine having to write out ten million, one hundred thousand, two hundred and three plus two!
Now imagine having to write out names!
Why do you write with numbers (1,2,3, 10,100,203) than writing out their names?
In chemistry we use short-hand as well.
A chemical formula is a way of writing out what happens in an experiment
What is H20? Or CH4

6. Let’s talk compound vs. element:
Is it a compound or element? He

7. Let’s talk compound vs. element:
Is it a compound or element?
How many atoms?
CO2

8. Let’s talk compound vs. element:
Is it a compound or element?
How many atoms?
NaClO

9. Let’s talk compound vs. element:
Is it a compound or element?
How many atoms? Na

10. Let’s talk compound vs. element:
Is it a compound or element?
How many atoms?
(CH3)2CHOH

11. So remember this! Bonding Ionic Metal and non-metal
Charges have to cancel out when making the compound!
Covalent
Non-metal bond to non-metal
Sharing until the outer ring is full!

12. Chemical Formula:
What does shorthand mean?
How many atoms?
-H20
-C6H1206
-CH4
A chemical formula is a shorthand way to use chemical symbols and numbers to represent a substance.
Also shows how many atoms are in each kind of molecule
Important parts:
Elements symbol
Subscripts
Coefficients

13. Chemical Formula continued:
What does shorthand mean?
How many atoms?
-H20
-C6H1206
-CH4
Read page 339
Important parts:
Elements symbol—you know this already!
Subscripts
Number written below and to the right of the symbol
Stands for the number of atoms of that type of element O2
CO2
N2O

14. Chemical Reaction:
Think of this a piece of sheet music...
Cheat sheet time!
Reactants point to products
R  P
Chemical equation uses symbols and formulas to describe a chemical reaction.
Parts:
Reactants—starting materials
Products—what you make
Yield—this is the arrow sign
This usually means that energy is going in or out

15. H2O(l) + SO2(g)  H2SO3(g) Identify the part:
Is it a reactant or product?
How did you know?
H2O(l) + SO2(g)  H2SO3(g)

16. Identify the part: Is it a reactant or product? How did you know?
How many oxygens on this side?

17. NaHCO3 + CH3COOH CH3COO-Na+ + H2O + CO2
Identify the part:
Is it a reactant or product?
How did you know?
NaHCO3 + CH3COOH CH3COO-Na+ + H2O + CO2

18. C3H8 + 5 O2  3 CO2 + 4 H2O Identify the part:
Is it a reactant or product?
How did you know?
C3H8 + 5 O2  3 CO2 + 4 H2O

19. Pearls of Wisdom:
On your small sheet of paper, please list what you learned today.
Do you think you can tell me what I wanted you to learn?

20. Homework:
Have a great weekend!

21. Pancakes!