Warm Up: 3/1/13
1)What 2 pieces of information can you identify from a
chemical formula? (Ex: H2O)
2)What is the name for the number written to the lower
right of a chemical symbol? H2O
3)Determine the types and number of elements in each
of the following chemical formulas:
a) NH4Br
b) Fe2O3
c) KNO3
Chemical Formulas PT
1) Hydrogen
2) H20
3) subscript
4) Chlorine
5) metallic
6) 1 nitrogen and 3 hydrogen
- 1 Barium and 2 Chlorine
7) Difference is what they are & their
properties, Hydrogen Peroxide has 2 Oxygen
PT continued
8) 2 things - what atoms and how many
Skillbuilder
a. CO2 - 1 carbon 2 oxygen
b. Ammonia - NH3 - 1 nitrogen and 3 hydrogen
c. calcite - CaCO3 - 1 calcium, 1 carbon, 3
oxygen
d. Potassium Hydroxide - KOH - 1 potassium, 1
oxygen, 1 hydrogen
e. Baking Soda - NaHCO3 - 1 Sodium, 1
hydrogen, 1 carbon, 3 oxygen
Chemistry Unit
Andolino & Williams
A Quick Review - Atom
Defined - smallest building block of a
substance or element
A Quick Review -Molecule
Defined- smallest substance of a
compound composed of one or
more atoms chemically combined
A Quick Review
Element
Defined - pure substance made up of only one
kind of atom
All are listed on the Periodic Table of Elements
•
Examples: Calcium, Sodium, Nitrogen
A Quick Review - Compound
Defined - 2 or more elements that are chemically
combined to make a new substance
properties of the elements used to make the
compound are changed
•
Examples: Salt, Water, Alcohol
A Quick Review -Mixtures
Defined - 2 or more elements physically combined
elements used keep their original properties
•
Examples: salt water, trail mix, rice & beans, Pizza
Ways to separate a mixture
•
•
•
•
Boil to separate something that is dissolved
in water
Strain (filter)- separate sand/gravel
Density differences- scoop off less dense
material (salad dressing)
Magnet- separate magnetic things from a
mixture
Chemical Formula
Defined - way of writing one
molecule of a compound
Shows THREE things
the elements that make up the compound
o metallic element always goes first
o the number of atoms of each element called Subscripts
o
H2O = the 2 is a subscript.
( H= 2 and O= 1)
Challenge...Round 1
•
•
•
With your table mates - represent the
molecule projected on each slide.
Make sure you have the correct elements
combined to make the compound
Make sure you have the correct number
of atoms in each molecule to make the
compound
Water - H2O
1 molecule of Water has...
2 atoms of Hydrogen
1 atom of Oxygen
•
•
Colorless, Odorless Gas
Colorless, Odorless Gas
Colorless, Odorless
Liquid
Salt - NaCl
a molecule of salt contains
1 atom of sodium
1 atom of Chlorine
•
•
Shiny, Luster, Silver,
Highly Reactive, Solid
Yellow, Vaporizes,
Poisonous Gas
White, Crystals, Edible
Ammonia - NH3
Chalk - CaCO3
Methane - CH4
Hydrogen Peroxide - H2O2
Glucose - C6H12O6
Butane - C4H10
Baking Soda - NaHCO3
Citric Acid - C6H8O7
Aspirin - C9H8O4
Caffeine - C8H10N4O2
Citric Acid - C6H8O7
Sugar - C12H22O11
Solutions- is a well stirred mixture
Contains a solute and solvent
•
Solvent- substance which dissolves
the solute
Example: water, coffee or tea
WATER IS THE UNIVERSAL
SOLVENT
Solute – substance that is dissolved
into the solvent
Example: powdered drinks or sugar
Solute or Solvent?
Making a Solution
Solubility - how well a solute can be dissolved into a given amount of
solvent
•
Depends on the temperature
o Most substances become more soluble as the temperature increases
o As temperature increases liquid particles can move faster and
dissolve the solute at a faster rate
Example: Hot Coffee – sugar dissolves faster compared to an iced coffee
Depends on pressure - For gases only
 Pressure Decreases - allows gas molecules to be farther apart
o Gases become less soluble as the temperature increases (hotter).
The more energy the particles have the harder they are to trap.
 This is why soda goes “flat” after the cap has been removed.
 Pressure Increases – allows more gas molecules to be close together
o Gases become more soluble as the temperature decreases (colder).
The less energy the particles have the easier they are to trap.
o You tend to burp more when soda is cold!
Solubility graphs are used to summarize the solubility of
different substances at a given mass (grams) of water as
temperatures (º C) increase
• ABOVE the line the solution is
SUPER SATURATED
• BELOW the line the solution is
UNSATURATED
• ON THE LINE the solution is
SATURATED
Chemical Reaction
Defined - process in which new substances with
new chemical and physical properties are formed
Reactants
Products
substance changed
substance formed
What are chemical
reactions?
http://videos.howstuffworks.com/discovery/29
165-assignment-discovery-chemicalreactions-video.htm
Are these chemical
reactions?
Burning Paper
Rusting
Burning Gasoline
Digestion
Conservation of Matter
Defined - matter cannot be created or destroyed
in a chemical change
Mass of
Reactants
Mass of
Products
Chemical Equations
Defined - describe chemical reactions in a
simple way
"yield"
Reactants
Na + Cl
Products
NaCl
Coefficient is the number of units involved in a
chemical reaction.
2KI = the 2 represents a coefficient.
So, 2 KI units are involved in this reaction.
Or KI and KI
Examples:
2H2O
2NaCl
2CO2
How do YOU balance this equation? Use the chart below
Kinds of
Atoms
Ag
H
S
Ag + H2S
Number of Atoms

Ag2S +
H2
Unbalanced Equation
Kinds of
Atoms
Mg
O
Mg
+
Number of Atoms
O2

MgO
Unbalance Equation
Kinds of
Atoms
Cl
Na
Br
Number of Atoms
Cl2 + NaBr
 NaCl +
Br
Unbalanced Equation
Kinds of
Atoms
Cu
Cl
H
S
CuCl2
Number of Atoms
+ H2S
 CuS
+
HCl
Catalyst Lab