1. Types of Chemical Reactions
Review Part 1
Types of Chemical Reactions

2. Chemical Reactions a) Definition:
A reaction that alters the nature and characteristic properties of matter.
The atoms are rearranged.
New molecules are formed

3. Chemical Reactions b) Observable characteristics:
A chemical reaction occurs when:
A gas is released
Heat is absorbed (endothermic) or released (exothermic)
Light is emitted
The color changes
A precipitate forms

4. Chemical Reactions c) Types of chemical reactions: i) Basic reactions:
Synthesis
Two or more reactants become one product
Decomposition
One reactant is decomposed into two or more products
Oxidation
A reaction where one of the reactants is oxygen (O2)
Precipitation
A reaction where two liquid reactants form a solid product

5. Chemical Reactions ii) Other chemical reactions
Acid-Base Neutralization
Reactants: Acid + Base
Products: Water + Salt
Combustion
Type of oxidation that releases a large amount of energy
Combustion requires
Oxidation agent
Ignition temperature
Fuel

6. Cellular respiration:
Takes O2 + glucose to form CO2 +water + energy
Photosynthesis:
Takes CO2 + water + energy to form O2 + glucose

7. Review part 2
Solutions

8. Important Definitions
Molecule:
A group of two or more chemically bonded atoms
Ion:
- an atom that has become electrically charged by loosing or gaining one or more electrons
An ion is negatively charged when it has more electrons (-) than protons (+)
An ion is positively charged when it has less electrons than protons

9. Solutions Definition: a solution is a homogeneous mixture.
Composed of the solute (e.g. powder) and the solvent (what is in greater quantity e.g. water)
In an aqueous solution, water is the solvent.

10. Solutions A) Characteristics of solutions 1. Solubility
2. Concentration
3. Electrical Conductivity
4. pH

11. A) Characteristics of solutions
1. Solubility
Definition the amount of solute that you can put into a solution
Many factors will affect the solubility of a substance:
The Temperature of the solvent
As temperature increase so does solubility for solids
The nature of the solvent

12. Properties of solutions
2. Concentration
Definition:
The amount of solute placed in a given solvent
Once the concentration of a solution reaches the solubility point we have a saturated solution
Can be measured in % (g/100ml)
Can be measured in g/L
Can be measured in ppm (g/ ml)
Can be measured in mol/L

13. 3. Electrical Conductivity
Definition:
The capacity of a solution to conduct electricity
Electrolytic solutions are solutions that contain electrolytes
Types of electrolytes
Acid
Base
Salts

14. Side note on acids: pH lower than 7 Release H+ ions
Often begin with an H followed by a non-Metal

15. Side note on bases: pH higher than 7 Release OH- ions
Often end with an OH

16. Side note on salts:
Combination of a non-metal and a metal

17. Characteristics of solutions
4. pH
Definition:
Scale that measures the concentration of H+ ions in a solution (measures the acidity)
The pH scale is a logarithmic scale, each level is ten times more acidic than the previous.

18. Identifying solutions
In order to identify an unknown solution there are many basic test to conduct:
Cobalt Chloride
Identifies if the unknown is an aqueous solution (if there is water in the solution)
pH paper, red litmus, blue litmus
Identifies if the unknown is an acid or a base
Electrical conductivity
Identifies if the unknown is an electrolytic solutions (if it contains an acid, a base or salt)