Molar Volume

 STP?

• standard temperature (0°C) or (273.15 k) and pressure (1 atmosphere)  
• where one mole of gas occupies 22.4L 

Molar Volume?

• the volume occupied by one mole of gas

 How to find Molar Volume

Conversion from Moles to Molar Volume

Conversion from Molar Volume to Moles

Isn't that a simple task!?

Here is an online worksheet with some questions! don't look at the answers before you're finished so you can challenge yourself! (:

Molar Volume worksheet!

Do questions 6, 9, 10, 11 and 12

Here's a game you can play with Molar Volume!

FUN GAME! (:

Molar Mass

• The mass (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

So what exactly is Molar Mass? 
 Molar mass is the atomic weight of an element expressed in grams is the mass of 1 mole of element.


How do you determine Molar Mass in a Compound?
To determine the molar mass of a compound you must ADD all the mass of the atoms together

Here's an explanation that will help you understand what Molar mass is:
 Follow these steps to find molar mass! What is the molar mass of H20? (water)

1. Identify how many atoms of each of the elements are in the chemical formula. In the example there are 2 atoms of Hydrogen and there is 1 atom of Oxygen.
2. Look at the periodic table and search for the elements given & then look at each of their atomic masses. The elements in H20 are Hydrogen and Oxygen. The atomic mass for Hydrogen is 1.0 amu and the atomic mass for Oxygen is 16.0 amu
3. Now multiply the number of atoms found in the chemical formula with the atomic mass.                        2 atoms of Hydrogen --->2(1.0) + 1atom of Oxygen-----> 16.0= 18.0 g/mol

So now that you have a basic foundation of what Molar Mass is now its YOUR TURN to do some practice problems! Answers will be provided at the bottom of the last question. ( but don't look straight into the answers you need to TRY some problems and then check if u understand it)  :)

• What is the molar mass of NO2?

• What is the molar mass of NaCl?

• What is the molar mass of FeO?

• What is the molar mass of NaNO3?

Answers:
NO2: 14.0 + 2(16.0)= 142.1 g/mol
NaCl: 23.0 + 35.5= 58.5 g/mol
FeO: 55.8 + 16.0= 71.8 g/mol
NaNO3: 23.0 + 14.0 + 3|(16.0)= 85 g/mol


Mole Conversions
To convert between moles & mass we use molar mass as the conversion factor. You must also be sure to cancel the appropriate units.

Here's an example: How many grams is there in 1.5 mol of 02?


1.5 Mol x     32.0   g   = 48.0 g
                     1 mol

Now you TRY!

How many moles are there in 115g of Fe203?


A sample of HCL contains 0.54 mol. How many grams of HCl is this?

Avagadro's Number and the Mole:

As we know, atoms and molecules are extremely small and microscopic objects contain too many of them to count or weigh individually. 

However, Amedeo Avogadro proposed a solution to this problem...

• the # of atoms in 12.00000 g of Carbon would be equal to a constant (this is = to 1 mole of carbon).
• this value is now called Avagadro's # and forms the basis of all quantitative chemistry

 So what is Avagadro's #?

1 Mole = 6.02 x 10^23


But What's a Mole?  

A mole is simply a multiple of things  

• 1 pair = 2
• 1 dozen = 12
• 1 century = 100  years
• So... 1 mole = 6.02 x 10^23              

How Big is a Mole?

• 1 mole of meters would cross the entire galaxy!
• $mole would be enough to give every person on earth 1 million billion dollars

You can also identify 1 mole as 602 000 000 000 000 000 000 000... 

                                                                             
Particle                                                                 
Atom:         Element            6.02 x 10^23
                                                 1 mole        Fe     
Molecule:   Covalent           6.02 x 10^23
                   Compound            1 mole        CO2  
Formula      Ionic                6.02 x 10^23
Unit:           Compound            1 mole        NaCl 

^ Example of using the mole:

• A sample of Carbon contains 3.78 x 10^24 atoms.  How many moles of carbon is this?

1. 3.78 x 10^24 atoms x 1 mole / 6.02 x 10^23 atoms
2. 3.78 x 10^24 / 6.02 x 10^23 (when doing this equation on your calculator you want to press "2nd ," which gives you EE.  This replaces the 10 and gives you a more precise answer)
3. this equation cancels out the unit atoms leaving us with the amount of moles...
4. thus your final answer is 6.28 moles

Another Example:

• Say you have 15.25 moles in a compound.  But you want to know the amount of molecules in the substance.  How would you solve this problem? 

1. 15.25 moles x 6.02 x 10^23/ 1 mole 

• But how did we figure our the ratio of molecules to moles?  You look at the chart above the first example!  Simple as that.  

    2.  15.25 moles x (6.02 x 10^23)... don't forget to use the "2nd ," instead of "x 10"
    3.  this equation cancels out the unit for moles and leaves you with the amount of molecules in the 
         substance 
    4.  your final answer is 9.1805 x 10^24 molecules 

Molecular Compounds

Naming Molecular Compounds

• Use the 1st name of the element
• 2 elements end in -ide
• 1 atom usually does not have a prefix. NO---> Nitrogen monoxide
• Hydrogen does not get a prefix

* Also be aware of the Latin prefixes. They are very important!!

Heres a link to a Molecular Compound Worksheet :)

thttp://www.docstoc.com/docs/2786822/Binary-Molecular-Compounds-Worksheet-1

Acids and Bases

Terms:

Acid:A solution that has an excess of H- ions. It comes from the Latin word acidus that means "sharp" or "sour". 

Base: A solution that has an excess of OH- ions. Another word for base is alkali

Acids & Bases have different properties...

Classical Names:

• Ferr- Iron
• Cupp-Copper
• Mercur-Mercury
• Stann- Tin
• Aunn- Gold
• Plumb- Lead

Naming acids
 *use the suffix- ic & or the prefix hydro
*Hydrogen appears first in the formula unless it is part of a polyatomic group

ex: sulfuric acid

      hydrochloric acid

• Hydrogen Compounds are acids
• HCl---->Hydrochloric acid

*IUPAC system was the aqeuous hydrogen compound

                                           Acids/ Bases to memorize

Naming Bases

*Use the cation name followed by hydroxide
- Sodium Hydroxide
- Barium Hydroxide

E.g: HI---> Iodic acid
       HBR---> Hydrobromic acid
       HOOCCOOH---> Oxalic acid

Here's a video that nay help you in Naming acids and Bases

            Hydrates

• These crystals contain water inside them which can be released by heating.

        Naming Hydrates

*These easy steps will help you ensure you get Hydrates right

1. Write the name of the chemical formula

2. ADD the prefix & # of water molecules

3. After the prefix add the hydrate

Here are some examples:

gfsgag

Electron Dot Diagrams

• The nucleus is represented by the atomic symbol
• For individual elements, you have to determine the number of valence electrons, which are represented by the dots around the atomic symbol
• To find the number of valence electrons is simple, look at the group number the element is in and that shows you the number of valence electrons
• There are four orbitals on each side of the nucleus holding a maximum of two electrons
• Each orbital gets 1 electron before they pair up, making a lone pair

 

Here are some examples of electron dot diagrams for sodium, magnesium and chlorine

Lewis diagrams for compounds and ions

• In covalent compounds, electrons are shared

Follow these two easy steps and learn how to draw a Lewis diagram for compounds and ions

1.       Determine the number of valence electrons for each atom in the molecule, which I explained above

2.       Place atoms so that valence electrons are shared to fill each orbital

This example shows the Lewis diagram for NF3

Double and triple bonds

Helpful Hint: Sometimes the only way covalent compounds can fill all their valence levels is if they share more than one electron

Lewis diagrams: Ionic compounds

• In ionic compounds electron transfer from one element to another
• Determine the number of valence electrons on the cation. Move these to the anion
• Draw [ ] around the metal and the non-metal
• Write the charges outside the brackets

Trends On the Periodic Table

Elements close to each other on the periodic table display similar characteristics.
- There are SEVEN important periodic trends:
1) Reactivity
2) Ion Charge
3) Melting point
4) Atomic Radius
5) Ionization Energy
6) Electronegativity
7) Density
We will only be talking about the first 6, today!

REACTIVITY:

•  metals and non-metals show different trends.
•  the most reactive metal is Francium; the most reactive non-metal is fluorine.

ION CHARGE:

• Elements ion charges depend on their group (column).

MELTING POINT:

• elements in the center of the table of the highest melting point.
• noble gases have the lowest melting points.
• starting from the left to right, melting point increases, until the middle
• carbon is an exception!

ATOMIC RADIUS:

• radius decreases to the up and the right.
• helium has the smallest atomic radius.
• Francium has the largest atomic radius.

IONIZATION ENERGY:

• ionization energy is the energy needed to completely remove an electron from an atom.
• it increases going up and to the right.
• all noble gases have high ionization energy.
• helium has the highest ionization energy.
• francium has the lowest ionization energy.
• opposite trend from atomic radius.

ELECTRONEGATIVITY:

• refers to how much atoms want to gain elections.
• same trend as ionization energy.