Moles to Volume Conversion

- At a specific pressure and temperature one more of every gas has the same volume
- At 0 degrees celsius and 101.3kPa 1mol = 22.4L
- This Temperature and pressure is called STP
- 22.4L/mol is the molar volume at STP
ex
2.5mol x 22.4L = 56L
               1 mol

11.6L x 1 mol = 0.518mol
             22.4L

11.5mol x 22.4L = 258L
                1 mol

1cc = 1mL
1cm^3 = 1mL

- JanCarlo Paysan

converting from moles to molecules

converting 2 moles of Au

like converting distance:
  
2 mol x 6.02x10^23 
                  1 mol

the mole's cancel each other out so you get  

2      x 6.02x10^23      = 12.01x10^23    = 12.0x10^23
                   1


you multiply and then convert to significant digits.

-Paul Dinh

Molar Mass (Mass of Atoms)

•The mass (in grams) of 1 mole of a substance is called the molar mass.
•It can be determined from the atomic mass on the periodic table
•Measured in g/mol
*Molar Mass* -The atomic weight of an element expressed in grams is the mass of one mole of the element. 

Molar Mass of Compounds

•To determine the molar mass of a compound add the mass of all the atoms together.

-Paulo Santillan

Avrogado's Number (How we count atoms)

•Atoms & molecules are extremely small
•Macroscopic objects contain too many to count or weigh individually
•Amedeo Avrogado proposed that the # of atoms 12.00000g of Carbon be equal to a constant (This is equal to 1 mol of Carbon)
•This value is now called Avrogado's Number & froms the basis of all quantitative chemistry.
• Avrogado's Number → 1mol = 6.02x10^23
•One mole is simply a multiple of things, such as:
∟1 pair = 2
∟1 dozen = 12
∟1 century = 100
∟1 mol = 6.02x10^23
•One mole represents a huge # of particles:
Particle                                                                                                                         
•Atoms                       Element                             6.02x10^23             Fe
                                                                                1 mol                                                             
•Molecules                 Covalent Compound            6.02x10^23             CO2     
                                                                                1 mol                                                                 
•Formula Unit             Ionic Compound                 6.02x10^23              NaCl
                                                                                1 mol
_____________________________________________________________________________
                     

 

                              

-Paulo Santillan  

Chem Lab

in lab we did we had to pick a hydrate and follow the steps
1) we had to weight the empty dry test tube
2) we had to weight the test tube with the hydrate in it
3) we had to light the bunsen burner
4) we had to boil all the water out of the hydrate
5) once we boiled all the water out we had to weigh the hydrate again
6) we calculated how much grams of water was boiled off and how much percent of water the hydrate was
7) we had to calculate our percent error for the percentage of water boiled off

- JanCarlo Paysan

Naming Compunds

Chemical Nomenclature

•IUPAC (International Union of Pure and Applied Chemistry) is today's most common system for most chemicals.
∟ Ions
∟ Binary Ionic
∟ Polyatomic Ions
∟ Hydrates
∟ Molecular Compounds
∟ Acids / Bases

Chemical Formulas
•Be aware of the differences btwn. ion & compound formulas:
EX: Zn^2+ → Ion charge (Zinc Ion)
BaCl2 → Number of Ions
F^- = Fluoride Ion
N^3- = Nitride Ion
0^2 = Oxide Ion
-Hydrogen (Hydride) = Both metallic & non-metallic

Multivalent Ions

•Some elements can form more than one ion:
EX: Iron → Fe^3+ / Fe^2+
Copper → Cu^2+ / Cu^+
•The top # on the P.T is more common
•IUPAC uses roman numerals in parenthesis to show the charge
•Classical systems uses latin names of elements & suffixes -ic(larger charge) & -ous(smaller charge)
EX: Ferr(ic) Oxide → Fe2O3 (Fe^3+)
Ferr(ous) Oxide → FeO (Fe^2+)

Other Classical Names

•Ferr= Iron •Aunn= Gold
•Cupp= Copper •Plumb= Lead
•Mercur= Mercury •Wolf= Tungsten
•Stann= Tin •Argent= Silver

Hydrates

•Some compounds can form lattices that bond to water molecules.
∟Copper Sulfate ∟Sodium Sulfate
•These crystals contain water inside them which can be released by heating
•To name hydrates
1) Write name of the chemical formula
2) Add a prefix indicating the number of water molecules (mono=1/di=2/tri=3/etc)
3) Add hydrate after the prefix
EX: Cu(SO4)•5H2O(s)
∟Copper(II) Sulphate
∟5 Water
∟pentahydrate

-Paulo Santillan

Electronic Structure ( Electron Dot Diagrams)

Drawing Electron Dot Diagrams
- The nucleus is represented by the atomic symbol
- For individual elements determine the number of valence electrons
- Electrons are represented by dots around teh symbol
- Four orbitals (one of each side of the nucleus) each holding a maximum of 2e-
- Each orbital gets 1e- before they pair up



Lewis Diagrams for Compounds & Ions
- In covalent compounds electrons are shared
1) Determine the # of valence e- for each atom in the molecule
2) Place atoms so that valence electrons are shared to fill each orbital

Ionic Compounds
- In ionic compounds electrons transfer from one element to another
1) Determine the # of valence electrons on the cation (+)
2) Move these to the anion (-)
3) Draw [ ] around the metal and non-metal
4) Write the Changes

- JanCarlo Paysan