Moles to Volume Conversions

  Some important facts to remember when converting from moles to volume are:

-At a specific pressure and temperature, 1 mol of gas occupies the same volume.

-> At 0º C and 101.3 kPa, 1 mol = 22.4 L

  Therefore, the number of atoms there are of a gas is irrelevant in converting as every gas will occupy the same volume. STP, or Standard Temperature and Pressure is another more convenient way to refer to 0ºC & 101.3 kPa. At STP, 22.4 L/mol is molar volume.

EXAMPLE:

  How many litres exist in 3.5 mol of Oxygen (O2)?

1. Write out what you know and what you want to find out.

2.5 mol   x   22.4 L   =  ?  L

     1 mol

2. Cancel out what you can and solve accordingly.

2.5 mol   x   22.4 L   =   56 L

  1 mol

*ALWAYS REMEMBER TO PUT THE APPROPRIATE NUMBER OF SIGNIFICANT DIGITS

EXAMPLE:

  Chlorine (Cl2) occupies 240 mL. How many moles exist?

1. Convert mL to L.

240 mL   x   1 L   =   0.240 L

 1000 mL

2. Write what you know and what you want to find out.

0.240 L   x   1 mol   =   ? mol

   22.4 L

3. Cancel out what you can and solve accordingly.

0.240 L   x   1 mol   = 0.0107 mol

22.4 L

*ALWAYS REMEMBER TO PUT THE APPROPRIATE NUMBER OF SIGNIFICANT DIGITS

http://www.youtube.com/watch?v=AHqNiEwcXiE

Avagadro's Number

-Atoms and molecules are extremely small.
-Macroscopic objects contains too many to count of weigh individually.
-Amedo Avagardo proposed that the number of the atoms in 12.00000g of carbon be equal to a constant(this is equal to 1 mol of carbon)
-This value is now called Avogadro's number and forms the basis of all quantative chemistry.
Avogadros Number
6.02x10e23      atoms over mol


http://sciencelost.com/images/mole2.jpg
http://ny-image2.etsy.com/il_fullxfull.95300322.jpg

Molar Mass & Molar Conversions

  Molar Mass can be defined as the mass in grams(g)of 1 mole in a substance. Therefore, it would be measured with the units grams per mole (g/mol). This number can be determined by looking at the atomic mass on the periodic table as the atomic weight of an element in grams is one mole of that element.

Molar Mass of Compounds
 
The molar mass of compounds is determined by adding the mass of all the atoms in the compound. Here are some steps to follow:


1. Find the individual masses of each element.

EXAMPLE:
H2SO4 -> Hydrogen: 1.0 amu, Sulfur: 32.1 amu, Oxygen: 16.0 amu
H2SO4 -> 1.0 + 32.1 + 16.0

2. Check to see if the number of atoms of each element correspond with the formula. Add any necessary changes.

EXAMPLE:
H2SO4 -> 2(1.0) + (32.1) + 4(16.0)
H2SO4 -> 2.0 + 32.1 + 64.0


3. Add all masses together with proper significant digits and units.


EXAMPLE:
H2SO4 -> 98.1 g/mol
H2SO4 -> 98 g/mol

  There may be cases where you may have to convert between moles and mass. In these cases, use molar mass as your conversion factor.

EXAMPLE:
  Determine the mass(g) in 3 mol of Oxygen.

1. Write out what you know, and what you want to find out.

3 mol of O    x          3(16.0) g          = ? g
                                 1 mol

2. Cancel out anything that you can.

3 mol of O    x          48 g                =? g
                              1 mol

3. Do any more calculations accordingly and write answer with proper significant digits and units.

 3(48g)     = 114 g of O
     1 

  You can do the same when finding the number of moles in a certain number of grams; just place the units in the correct part of an equation and repeat the steps!

http://www.youtube.com/watch?v=m8JYa5DZv2o&feature=related 

LAB TIME!!!

Today we did an experiment dealing with hydrates!

What are hydrates you ask? Well they are simply Compounds that are bonded along with H20 (water)

Ok, so in the lab we are comparing the hydrate and anhydrates of colbalt chloride hydrate

We started the lab by...of course safety equipment.

Then we did the lab (which was basically using the bunsen burner to evaporate the water inside the colbalt hydrate.

Things I noticed in the lab...
1) The hydrate at the start was crimson, and during the evaporation part, it started bubbling and turned a royal blue, then as we kept on evaporating, it turned into a really light blue.

2) Some of my peers also had "plaque", as my teacher said. and it was due to overheating???? not sure

3) After we evaporated the water, guess what? its lighter. of course....

Cobalt Chloride Hydrate

Cobalt Chloride

Naming Compounds

Chemical Nomenclature

  Currently, the most common system that is being used to for most chemicals is the IUPAC system, otherwise known as the International Union of Pure and Applied Chemistry. This system can be used to name:

-> ions

-> binary ionic

-> polyatomic ions

-> molecular compounds

-> hydrates

-> acids & bases

Chemical Formula

  In order to write a chemical formula, you would have to be aware of the differences between ion and compound formulas. 

EXAMPLE: The picture above shows examples of ions. Ions have either a negative or a positive charge. If they have a positive charge, they are called CATIONS and if they have a negative charge, they are called ANIONS.

 EXAMPLE: The chart above has examples of compounds. They show what elements are there and how many of each exist.

Multivalent Ions

  Important ideas to keep in mind with multivalent ions are:

1. Some elements can form more than one ion

2. IUPAC uses roman numerals in parenthesis to show charge

3. Classical systems consisting of Latin names & suffixes may be used:

   -> The suffix "ic" is added at the end to represent the larger charge

   -> The suffix "ous" is added at the end to represent the smaller charge

   -> Classical names used for certain elements are:

         -Ferr = Iron

         -Cupp = Copper

         -Mercur = Mercury

         -Stann = Tin

         -Aunn = Gold

         -Plumb = Lead

EXAMPLE: The picture above is an example of how certain suffixes or names are subbed in to the formula.

Hydrates

  Hydrates are compounds that include H2O. These compounds form lattices that bong to water molecules and when heated, the H2O can be released.

  In order to name hydrates, you must:

    

    1. Write out the chemical formula.

    2. Add prefixes indicating the number of water (H2O) molecules exist.

    3. Add the hydrate (H2O) after the prefix.

EXAMPLE: COPPER (II) SULPHATE PENTAHYDRATE -> Cu (SO4) x 5H2O

                  LITHIUM PERCHLORATE TRIHYDRATE -> Li(ClO4) x 3H2O 

Molecular Compounds

  These can be created by adding prefixes to the elements to indicate how many of each element exists in the formula. As for a suffix for the latter part of the formula, you can add "ide".

EXAMPLE: DiNitrogen TetraOxide -> N2O4

                  TetraPhosphorous DecaOxide -> 3P10O

Naming Acids & Bases

 Hydrogen compounds are ACIDS:

   -> HCl = Hydrochloric Acid*

    -> CH3COOH = Acetic Acid* (Vinegar)

*Take note of hydrogen and the endings,

  

 Hydroxide (OH) compounds that include cations are BASES:

    -> NaOH = Sodium Hydroxide*

   -> Ba(OH)2 = Barium Hydroxide*

*Take note of the hydroxide ion.

Naming Ionic Compounds Video:

http://www.youtube.com/watch?v=7Lfc6jjp1WQ

Lewis Diagrams (sports update canucks over the oilers 4-3)

Electron Structure

-Drawing Electron Dot Diagrams

- The nucleus is represented by the atomic symbol.

-For individual elements determining the number of valence electrons

-Electrons are represented by dots around the symbol

-4 orbitals ( one of each side of the nucleus each holding a max of 2e-

-each orbital get 1e- before they pair up




http://www.green-planet-solar-energy.com/images/carbon-hydrogen-e-dots.gif




Lewis Diagrams for Compounds and Ions

-In a covalent compounds electrons are shared

1)Determine the number of valence e- for each atom in the molecule

2)Place atoms so that valence e- are shared to fill each orbital




http://www.walkingrandomly.com/images/chemistry/lewis-ethane.gif




Double and Triple Bonds

-Sometimes the only way covalent compound can fill all their valence levels is if they share more than on electron




http://www.fordhamprep.org/gcurran/sho/sho/images/lewdot11.jpg




Ionic Compounds

-In ionic compounds electrons transfer from one element to another

-Draw [] around the metal and non-metal

-Write the changes on the outside brackets




http://www.kentchemistry.com/images/links/binding2/covale9.gif




Lewis Diagrams for Polyatomic Ions

1) Determine the number of valence e- for each atom in the molecule

2)Subtract on electron for each + valence electron charge

3)Add one electron for each - valence electron charge



http://www.glencove.k12.ny.us/highschool/ChemRev/CovBond.jpg

VIDEO!!!!!!
http://www.youtube.com/watch?v=GFIvXVMbII0


Periodic table trends: 1. Elements close to each other on the periodic table
                                         display similar characteristics
                                     2. There are 7 important periodic trends: a. reactivity
                                                                                                   b. ion charge
                                                                                                   c. melting point
                                                                                                   d. atomic reactions
                                                                                                   e. ionization energy
                                                                                                   f. electro negativity
                                                                                                   g. density

Reactivity: 1. Metals and non-metals show different trends
                   2. The most reactive metal is Francium; the most reactive non-metal is Fluorine

Ion charge: 1. Elements ion charges depend on their group [column ]

                      

Melting point: 1. Elements in the center of the table of the highest melting point
                         2. Noble gases have the lowest melting points
                         3. Starting from the left and moving right, melting point increases [until middle of the table]

Ionization Energy: 1. Ionization energy is the energy needed to completely remove an electron from an atom
                               2. It increases going up and to the right
                               3. All noble gases have high ionization energy
                               4. Helium has the highest ionization energy
                               5. Francium has the lowest ionization energy
                               6. Opposite trend from atomic radius

Electronegativity: 1. Electronegativity refers to how much atoms want to gain electrons
                               2. Same trend as ionization energy