Organic Chemistry (April 30, 2010)

What is organic chemistry? For starters, it is the study of carbon compounds. Also, know that carbon can have multiple bonds and form many different things.

What are the 3 types of hydrocarbons? Alicyclics, aromatics and aliphatics are 3 types of hydrocarbons. However, Alkanes, alkenes and alkynes all fall under the category of aliphatics.

What are the 3 types of formla's for hydrocarbons?

1)Molecular formulas (Example: C6H14)

2) Condensed Structural formula (Example: CH3 - CH2 - CH2 - CH2 - CH2- CH3)

3) Structural Formula

Describe a characteristic of the nomenclature of hydrocarbons. Only one molecular formula can have a number of different structures. Also, isomers are compounds that can be drawn in more than one way.

Example: butane C4H10 CH3 - CH2 - CH2 - CH3

How do you name Alkanes (that all have single bonds)?

1) Name the longest chain by using the correct suffix and adding "ane"

2) Locate any branches by numbering carbon atoms. (*Use the lowest possible number system*)

3) Name branches by using appropriate suffix and -yl ending (alkyl branches)

4) If there are more than one of the same alkyl group, number each one and add the multiplier number in front of the branch name.

Examples:

Below is a picture of a chart that includes the number of carbon atoms, stem name, side chain (Alkyl group) name, and the multiplier. It will help you very much when naming hydrocarbons.

UNIT - REVIEW CLASS (April 26, 2010)

-Today we had a class to review the whole unit consisting of these three chapters: Solution -Chemistry, Intermolecular Bonds, and Ions in Solutions
We pretty much had the entire class to review the unit as well as working with the review sheet

Here's an example question from the worksheet:
1) Definition of a Solute:
- It's the substance present in smaller amount
Definition of Solvent:
- The substance present in greater amount

Be sure to complete the review sheet and GOOD LUCK ON YOUR TEST!

Ions in Solutions ( April 23 class)

The formation of a solution depends on the ability of the solute to dissolve in the solvent
Solvation- interaction between solutes and solvents
Ionic Solids- crystals made up of ions (salts)
Molecular Solids- crystals made up of neutral molecules
Dissolving ionic solutions produces ions in a process called - Dissociation
Ionizaiton - the break up of a neutral molecule into charged particles

Examples:
1) FeCl3 (s) ----->Fe 3+ (aq) + 3 Cl -1 (aq)
2) Ag2O (s) -----> 2 Ag + (aq) = O 2- (aq)
3) Na3PO4(s) -----> 3 Na + (aq) + PO4 (aq)
4) (NH4)2SO4 (s) -----> 2NH4 + (aq) + SO4 2- (aq)


Determining concentrations is relatively easy.

Examples:
What is the [Cl-] in a solution of 0.50 M AgCl3?
AgCl3 -----> Ag + (aq) + 3Cl- (aq)
Cl = 3x as many moles = (0.5 M) x 3 = 1.5 M

What is the [NO3-] in a solution of 0.82 M Fe(NO3)2?
Fe(NO3)2 -----> Fe 2+ (aq) + 2 NO 3- (aq)
(0.82 M) x 2 = 1.64 M

What is the [Cr2O7 2-] and [K+] when 3.5 g of K2Cr2O7 dissolved in 40 mL of water?
K2CrO7 -----> CrO7 2- (aq) + 2K + (aq)
3.5 g x 1 mol/294.2 g = 0.0

Intermolecular Bonds

Are: - Bonds between molecules
- There are three types



1) London Dispersion Force (L.D.F)
- weakest intermolecular force
-results in temporary electron dipoles
- increases as number of electrons increase
- occurs in any compund that has electrons (everything)

eg: Br has a higher L.D.F. than Cl

2) Dipole-Dipole Force
- results from a permanent dipole in molecules
- polar molecules experience this force
- polarity depends on how much an element wants electrons (electronegativity)
- strength of a dipole-dipole bond depends on the difference in electronegativity between 2 atoms

3) Hydrogen Bonds (H-Bonds)
- this is a special type of dipole-dipole bond between H and O, F or N
- Any molecule that has H-F, O-O, H-O or H-N

Diople-Diople Force Diagram

Short Video Clips

http://http//www.youtube.com/watch?v=3t1Jn_jrsQk&feature=related

http://www.youtube.com/watch?v=lkl5cbfqFRM&feature=related

POLAR/NONPOLAR LAB

Today's lab was on polar and non polar solutions/substances. We took paint thinner, water, glycerin, salt and sugar. We mixed them accordingly, and learned that paint thinner and water do not mix because water is nonpolar and paint thinner is polar. This then draws our conclusion that "likes" mix, and differences DON'T mix. Polar mixes with polar, and nonpolar mixes with nonpolar. Although the paint thinner and water were almost the same colour, you were able to see the layer where they met. Salt didn't dissolve in the paint thinner, also because they are not "alike."

Conductivity (April 14,2010)

In the beginning of class, we checked the conductivity of distilled water by itself, which turned out to be 0. However, when we add salt to it, the conductivity immediately got higher. Afterwards, we decided to see what the conductivity of tap water is, which not surprisingly turned out to be 0 as well. But when we added salt to it, once again, it quickly got higher. After this mini experiment, we learned how to tell whether solutions could be conductive, or non-conductive.

Electrical conductivity in solutions requires charged ions to be present.
Ionic solutionsassociate (split) when placed in water
Examples:

Molecular solutions don't usually split into ions.Follow these steps to determine conductivity:

LAB - SOLUTIONS ACTIVITY

(Sorry for a late post!)

The class started off quick because we had a shortened block due to the prayer service. Mr. Doktor gave us a quick explanation of what the lesson was: to the the conductivities of different soloutions.

Solutions Chemistry (March 30 2010)

The study of chemical reactions in a solution
A solution is a homogeneous mixture
Solvent are components present in larger amounts
Solutes are componets present in smaller amounts
A solute is soluble in a solvent if it dissolves to form a homogenous mixture
A saturated solution contains as much solute as possible
An unsaturated solution can dissolve more solute
Solubility is the measure of how much solute can dissolve in a given
solution (g/L, g/ml, mol/L, ppm)
The solubility of Ba (NO3)2in water is 63 g/100 mL @ 25 degrees Celcius while
the solubilty of Ba(NO3)2 in alcohol is is 1.6 g/ 100 mL @ 25 degrees Celcius

Factors that affect solubility:
Temperature (heat)
changing solute
changing solvent