Ch.12 Alkanes Flashcards
These are hydrocarbons that have C-C and C-H bonds. The carbons can be joined together to form chains or rings of atoms.
Alkanes
Alkanes that contain chains of carbon atoms but no rings.
Acrylic alkanes
What is the molecular formula for acylic alkanes?
CnH2n+2
n=# of carbons
What is another term for acylic alkanes and why is it called this?
saturated hydrocarbons because they have a maximum number of hydrogen atoms per carbon.
These are alkanes containing carbons joined in one or more rings
Cycloalkanes
What is the molecular formula for cycloalkanes?
CnH2n
This is a chemical substance used for communication in animal species and is an acylic alkane? Has a molecular structure of C11H24
Pheromone
Acylic alkanes that have fewer than 5 carbons.
Simple alkanes
What are two types of simple alkanes?
Methane
Ethane
This has a single carbon atom
Surrounded by 4 hydrogen’s to give it 4 bonds.
Methane
This has 2 carbon atoms joined together by a single bond. Each carbon atom is bonded to 3 hydrogen’s to give it 4 bonds.
Ethane
Since each carbon in an alkane is surrounded by 4 atoms each carbon is _____ with bond angles of ______.
Tetrahedral
109.5
This has 3 carbon atoms single bonded in a row. Each carbon has hydrogen atoms bonded to give it 4 bonds.
Propane
This has 4 carbon atoms single bonded in a row with hydrogen atoms bonded to each to give it 4 bonds.
Butane
This has 3 carbon atoms in a row and one carbon bonded to the middle carbon. Has enough hydrogen atoms on each carbon to give each carbon 4 bonds.
Isobutane
Isobutane and butane are _____. Two different compounds with the same molecular formula
Isomers
These are isomers that differ in the way atoms are connected to each other.
Constitutional isomers
As the number of carbon atoms in an alkane increases so does the number of _____.
Isomers
How many constitutional isomers are there for the 5 carbon alkane? And what are they called?
3
Pentane
Isopentane
Neopentane
Carbon atoms in alkanes and other organic compounds are classified by the number of other _____ directly bonded to them.
Carbon
A primary carbon is bonded to ____ other Carbon.
One
Secondary carbons are bonded to _____ other carbons.
Two
Tertiary carbons are bonded to ____ other Carbons.
Three
Quaternary carbons are bonded to _____ other carbons.
4
Rotation can occur around carbon-carbon ____ bonds.
Single
What does bond rotation allow?
Allows the hydrogen’s on one CH3 group to adopt different orientations relative to the hydrogen’s of other CH3.
What is the most stable arrangement of bond?
The most stable arrangements avoid crowding between nearby carbons.
IUPAC stands for what? And what is it?
International Union of Pure Applied Chemistry.
It’s used to name alkanes.
Most drugs have what 3 names?
Systematic
Generic
Trade
These are alkanes that have carbon branches.
Substituents
This indicates the number of carbons in the longest continuous carbon chain in the molecule.
Parent name
This indicates what functional group, of any, are present -ane indicates and alkane.
Suffix
This tells us the identity, location and number of substituents attached to the carbon chain.
Prefix
What is the order of naming substituents?
Prefix+parent+suffix
Carbon substituents bonded to a long carbon chain are called?
Alkyl groups
These are formed by removing one hydrogen from an alkane.
Alkyl group
How do you name an alkyl group?
Remove the -ane from the parent alkane and replace it with -yl
Example is methane to methyl
Name the steps taken in naming an acylic alkane.
- Find the longest continuous carbon chain. And name the parent. 6 carbons would be hexane.
- Number the atoms in the carbon chain to give the 1st substituent the lower number.
3 name the number of substituents. - Combine aubstituents names and numbers + parent + suffix
- Alphabetize the names of the substituents ignoring prefixes like di-
______ contain carbon atoms arranged in rings.
Cycloalkanes
What is the arrangement and angles of cycloalkanes with more than 3 carbons?
Chair form
109.5
Many alkanes occur in nature primarily in _____ and ____. Both of which are fossil fuels and serve as energy sources formed long ago from the degradation of organic material.
Natural gas and petroleum
What is natural gas composed of?
Methane with lesser amounts of Ethan, propane, and butane.
What is petroleum composed of?
A mixture of compounds, most of which are hydrogen’s containing 1-40 carbon atoms. It is nonrenewable.
Define refining.
Distilling crude petroleum. Separates it into usable fractions that differ in boiling points.
Alkanes contain only nonpolar C-C and C-H bonds so they exhibit only weak ______ _____.
Intermolecular forces.
Alkanes have ____ melting and boiling points.
Low
Melting and boiling points of alkanes _____ as the number of carbons increases.
Increases.
What reaction can an alkane undergo involving oxygen?
Combustion
When an alkane burns in the presence of oxygen to form carbon dioxide and water.
Combustion
Combustion is an example of what?
An oxidation-reduction reaction.
An increase in number of C-O bonds and a decrease in number of C-H bonds indicates what?
Oxidation.
A decrease in number of C-O bonds and a increase in number of C-H bonds indicates what?
Reduction
What happens during incomplete combustion?
Carbon monoxide is formed instead of carbon dioxide.
This is the reaction of an alkane with a halogen.
Halogenation.
What is formed during halogenation?
An alkyl halide and a hydrogen halide
Halogenation only occurs when the reactants are____ together or exposed to ____.
Heated
Light
Halogenation is an example of a ____ reaction.
Substitution
A reaction in which an atom is replaced by another atom or a ground of atoms.
Substitution reaction.
