1. Chemical vs physical properties

2. State of matter (solid, liquid, gas) Melting, freezing, boiling point
Elements and compounds can be described by their chemical and physical properties
Physical property: characteristic of a substance you can observe (using your senses) without changing it into something else
State of matter (solid, liquid, gas)
Melting, freezing, boiling point
Magnetism
Density
Color
Shape
Malleability
Solubility
Specific heat

3. Chemical properties: properties of an element or compound in a chemical reactionpH
Reactivity
Flammability/Combustion
Rusting
Bond

4. Practice on Identifying Chemical and Physical Properties
Water boils at 100 degrees Celsius.
Diamonds are capable of cutting glass.
Water can be separated by electrolysis into hydrogen and oxygen.
Sugar is capable of dissolving in water.
Vinegar will react with baking soda.
Yeast acts on sugar to form carbon dioxide and ethanol.
Wood is flammable.
Aluminum has a low density.
Ammonia is a gas at room temperature.
Bromine has a red color.

5. Most types of matter heat up at the same rate
Which of the following conclusions can be drawn from the information shown?
Most types of matter heat up at the same rate
Most types of matter cool at the same rate
It takes less energy to heat 1g of silver than 1g of gold
It takes more energy to heat 1g of water than 1g of copper
Material
Specific Heat
Aluminum
0.899
Copper
0.387
Gold
0.129
Silver
0.234
Water
4.182
Wood
0.176

6. Magnesium melts at 650°C. If a 100g sample of magnesium melts at 650°C, then a 75g sample would melt at:
325°C
650°C
487.5°C
162.5°C

7. Chemical change: atoms are rearranged, I have different substances at the end of a chemical reaction/change
Change in color
Formation of precipitate (L+LS)
Formation of a gas
Creation of light
Burning
Change in temperature (exothermic, endothermic)

8. Changes can be physical or chemical
Physical changes do not rearrange atoms, I have the same substance I started with. I can reverse a physical change Change in shape Change in phase Dissolving Reversable

9. Practice on Identifying Chemical and Physical Changes
Dry ice, solid carbon dioxide, is sublimed at room temperature.
Salt is dissolved in water.
Iron rusts in a damp environment.
Gasoline burns in the presence of oxygen.
Hydrogen peroxide decomposes to water and oxygen.

10. Combustion: reacting with oxygen frequently producting CO2& water
C3OH + O2  CO2 + H2O + heat 2Mg + O2  2MgO + Heat ______________________________________ 2H2 + O2  2H2O + heat NH4 + NO2  N2O + H2O

11. Compounds or molecules are represented using a chemical formula
Subscripts (little number) tell you the number of atoms in the 1 molecule of the compound
Coefficients (big number out front) tell you how many molecules
(no number means the number is 1!)

12. Calculate the number of atoms of each element
AgMnO4 AlBO2 CH3OH BaSi2O5

13. Calculate the total number of atoms of each element
2AgMnO4 6AlBO2 7CH3OH 2BaSi2O5 KNO3

14. Conservation of Mass
Mass on the reactant side of the equation equals the mass on the product side of the equation Number and type of atoms on the reactant side of the equation equals the number and type of atoms on the product side of the equation. Reactants Products

15. To check for balance, multiply coefficient x subscript
__H₂ __O₂  __H₂O
A. 1, 1, 1
B. 2, 1, 2
C. 2, 1, 2
D. 2, 2, 2
__K + __B2O3  __K2O + __B
A. 3, 2, 3, 2
B. 6, 1, 3, 2
C. 6, 2, 3, 2
3, 2, 2, 2
To balance an equation its cool to change coefficients, do not change subscripts….don’t mess w/the little people (you’ll change the molecule’s identity!)

16. Calculate the mass of the product of 6. 40 g of magnesium with 1
Calculate the mass of the product of 6.40 g of magnesium with 1.32 g of oxygen .
Calculate the mass of the zinc that reacts with 4.11 g of hydrochloric acid to form 9.1 g of zinc chloride and 3.97 g of hydrogen gas.
During the combustion of 5.00 g of Butane in the presence of oxygen, 4.01 g of carbon dioxide and 3.55 g of water is given off. How much oxygen was needed to totally combust the butane?

17. Review…..

18. Compound:
Made when two or more elements combine during a chemical reaction
Examples:
Water
Salt
Sugar
Chemical Change

19. Compounds are formed or separated through chemical reactions…
What is evidence that a chemical reaction is happening again?
Fire, Combustion, Explosion
A new color appears/disappears
Temperature change
Production of Gas, gas bubbles
Production of Precipitates

20. Mixture
Combines 2 or more substances without producing a chemical reaction
NOT the same throughout - heterogeneous
Can be separated easily
Examples:
Soil
Fruit salad
Physical Change

21. Solution: A type of MIXTURE that IS the same throughout - homogenous
Solute- substance being dissolved
Solvent- substance doing the dissolving
Examples:
Salt water
Lemonade
Physical Change
Salt = Solute
Water= Solvent
Salt Water= Solution