Mr. Bouyer
Day 1 | Day 2 - 3 | Lab | Skills Test

  • Name the first ten alkanes.
  • Write chemical formulas for alkanes.
  • Draw structural formulas for normal alkanes.
  • Name branched alkanes.
  • Draw structural formulas for branched alkanes.

Hydrocarbons:
substances composed of only hydrogen and carbon.

An underground hydrocarbon trap Hydrocarbons usually occur in specific types of rocks, principally shales. Organic remains gradually rot, and are buried and compressed by new sediments. Heat and pressure may change the carbon from the rocks into hydrocarbons. Oil tends to form in rocks whose carbon comes largely from marine plants and animals. Gas tends to form in deposits which contain carbon largely from land plants.

The hydrocarbons gradually seep from the source rock and travel along the path of least resistance. Since gas and oil are lighter than water, they tend to rise, collecting in pockets formed by rock traps. Traps occur where a layer of rock prevents the hydrocarbons from moving further upward.

Pumpjacks bring petroleum to the surface

Alkanes are produced by refining petroleum, link to an Internet Website shale oil, or coal. Many alkanes are used for fuels: methane as natural gas, propane in gas grills, and butane in lighters. Gasoline link to an Internet Website is a complex mixture of many alkanes. When alkanes react with chlorine, they produce compounds that are used as paint strippers and dry cleaning fluids. The anesthetic chloroform is a chlorinated hydrocarbon.


Alkanes follow this general formula: CnH2n+2

It is possible for a normal alkane to be bent without being branched.
 
n-pentane - it is bent, but not branched

The name of this compound is n-pentane.
The "n" means "normal".
 The name of this compound is 3-methylpentane
What is the name of this compound?

 

  1. Learn the names and formulas for the 10 alkanes above.
  2. Learn the general formula for alkanes.
  3. Be able to recognize the difference between a "bent" and a "branched" alkane.
  4. Be able to use the general formula for alkanes to give the formula for an alkane with any number of carbon atoms.

Day 2 - 3

Because of the bonding characteristics of carbon, organic molecules are the most complex in all of chemistry. A very strict system of nomenclature link to an Internet Website has been established for naming these complex chemicals based on their structure. Explore this Internet Website about Chemistry

Rules for naming branched alkanes:

  • The number of carbon atoms in the longest chain determines the parent chain of the compound. The parent name will end with "ane".
    • Number the carbons in the parent chain. Start at either end to use the lowest possible position numbers for the branch or branches.
  • Carbons not in the parent chain are named as radicals with a "yl" ending.
  • Write the position number of the branch first, with a hyphen between the number and the branch name.
  • Write the branch name and the parent name as one word.
  • If more than one of the same kind of branch is on the parent chain, prefixes are used instead of writing each branch separately.
    • A comma is placed between the position numbers of the branches that are alike.
  • If more than one kind of branch is found on the same parent carbon, the names are written in alphabetical order.
    • Place a hyphen between the branch types.

Refer to the names in the assignment below to see properly written names for branched alkanes.

Practice Problems: name the following branched alkanes.

Alkane #1 | Alkane #2 | Alkane #3 | Alkane #4 | Alkane #5      
 

 

link to an Internet website with useful information

Homework Assignment 323:
This assignment must be turned in by the beginning of class tomorrow to receive credit.
Scoring criterialink to a local webpage

  1. Name the alkanes represented by the structural formulas below:

    a.3,3-dimethylhexane
    b.2,4-dimethylhexane
    c.2,3,4-trimethylhexane
    d.3,3-diethylpentane

  2. Write the complete structural formula for the following alkanes:
    1. 2-methylpentane
    2. 2,2-dimethylpropane
    3. n-octane
    4. 3-ethyl-2,5-dimethylheptane
    5. 3-ethylpentane
Research Links:

Chemistry Class

 

 

 

 

 

 

 

 

 

  1. 3, 4-dimethylhexane

  2. 4-ethyl-4-methylheptane

  3. 3, 4, 5-trimethylheptane

  4. 2, 3, 4-trimethylhexane

  5. 3, 3-diethylhexane