(11) Hydrocarbons

chapter 14

What are hydrocarbons?

Simplest organic compounds contianing only two elements: hydrogen and carbon. Most are obtained from natural gas and petroleum by fractional distillation according to their boiling points

What does the physical state of hydrocarbon depend on?

the length of the carbon chain

What are alkanes?

carbons joined together with single bonds. they are named according to the number of carbon atoms in the chain and contain the suffix ane
(meth, eth, prop, but, the rest use latin number roots after)

How do you predic the number of hydrogens in any alkane?

use -C_nH_{2n_2}

Why are alkanes called saturated hydrocarbons?

Single bonds between adjacent carbon atoms allow attachment of the maximum number of hydrogen atoms

What is an alkyl group?

When hydrogen atoms are removed from alkanes, the type of formula changes. The new structure is no longer a complete compound, but a group of atoms capable of attaching to another atom where a hydrogen used to be. Repalce -ane with -yl

What are alkyl halides?

Alkyl groups that may attach to group 7a (halogens) on the periodic table
C_nH_2n+1X

When does the simplest alkyl halide occur?

When a hydrogen atom in methane is replaced by chlorine

In alkyl halides, replacement of additional hydrogen atoms by chlorine can yield:

-Methylene chloride
-Chloroform
-Carbon tetrachloride

What are isomers?

Two or more substance having the same molecular formula but different structural formulas (property of alkanes beginning with butane)

WHat is the IUPAC?

International Union of Pure and Applied Chemists. Used worldwide, allows chemists everywhere to communicate effectively

What are the 3 rules of the IUPAC?

1: Find longest carbon chain
2: Number the carbons
3: Locate and name any alkyl groups attached to the longest chain

What are alkenes?

Hydrocarbons that contain one double bond in the chain, or the simplest unsaturated hydrocarbons

What is the simplest alkene?

Ethene

What are unsaturated hydrocarbons?

Multiple bonds present in a carbon chain. Contains less hydrogen atoms than it could if only single bonds were present

How are the hydrogen atoms in alkenes determined?

With the formula C_nH_2n

One unsaturated hydrocarbon contains a triple bond between adjacent carbon atoms; the first members of this series are…

ethyne or acetylene

What are aromatic hydrocarbons?

Compounds that contain a benzene ring, or a system of them. THey can also be known as arenas. Get their name from their pleasant scents, include vanilla and oil of wintergreen

What is the structure of benzene?

-Molecular: C₆H₆
-Drawn with alternating double bonds between carbons

At room temperature and 1 atm, beneze is…

a colorless liquid that is insoluble in water

What are some physical properties of benzene?

-Extremely flammable
-Linked to certian blood disorders, like leukemia
-Good organic solvent
-Starting material for the synthesis of compounds like plastics, synthetic rubber, pharmaceuticals and pesticides

What creates a derivative of benzene?

When one hydrogen is replaced (monosubstituted)

What are some derivatives of benzene?

-Toulene (methylbenzene)
-Phenol (hydroxybenzene)
-Aniline (aminobenzene)

Where did toulene get its name from?

The fact that it can be obtained from the tolu tree

What is toulene used for?

-A good solvent for other organic compounds, such as paints and varnishes
-Starting material for the explosive trinitrotoluene

What is phenol?

Derivative of benzene contianing one or more -OH groups

What are some characteristics of phenol?

-Colorless
-Crystalline solids
-Soluble in water
-Weakly acidic (carbolic acid)

What was phenol used for in the 1860’s?

General disinfectant, discovered to be the active agent in german creosote which is a sewage treatment deodarant

How did Joseph Lister use phenol?

-Hy hypothesized that it could have some value in stopping postoperative putrefactive infections
-Soaked gauze dressings in various concentrations of phenol and applied them to compound fracture wounds of his surgical cases- dropped infections to 2%