__ are hydrocarbons with C=C. They are sometimes called __, a term derived from olefiant gas, meaning "oil-forming gas"
__ is the largest-volume industrial organic compound, used to make __ and a variety of other industrial and consumer chemicals. __ is a major component of __, the paint solvent distilled from extracts of evergreen trees. __ is the sex attractant of the common housefly.
Double bonds are ____ than single bonds.
This shows that pi bonds should be what?
more reactive than sigma bonds
Because a C=C is relatively __, it is considered a __, and alkenes are characterized by the reactions of their double bonds.
in ethylene, each C atom is bonded to __ other atoms (one carbon and two hydrogens), and there are no __. __ are needed, implying __ and a bond angle of __.
- nonbonding electrons
- three hybrid orbitals
- sp2 hybridization
Each of the C-H __ bonds is formed by overlap of an __ on carbon with the __ of a H atom. The C-H bond length in ethylene is __ than the C-H bond in ethane. Why?
The s orbital is __ to the nucleus than the __, contributing to __.
- sp2 hybrid orbital
- 1s orbital
- slightly shorter
- because the sp2 orbital in ethylene has more s character than an sp3 orbital
- p orbital
- shorter bonds
The remaining sp2 orbitals overlap in the region between the __, providing a __. The pair of electrons in this __ forms one of the bonds between the carbon atoms. This bond is a __ because its __ is centered along the line joining the nuclei.
- carbon nuclei
- bonding orbital x2
- sigma bond
- electron density
Why is the C=C bond shorter than the C-C bond?
sigma bond of ethylene is formed from sp2 orbitals and because there are two bonds drawing the atoms together
For pi overlap to occur, the p orbitals must be __, which requires that the two carbon atoms be oriented with all their C-H bonds in a __.
Half of the __ is above the __, and hte other half is __. The pi-bonding electrons give rise to regions of __.
- single plane
- pi-bonding orbital
- above the C-C sigma bond
- below the C-C sigma bond
What is the restriction of double bonds?
rotation is restricted
Alkenes are said to be __ because they are capable of adding H in the presence of a catalyst. The product, an __, is called __ because it canot react with any more hydrogen.
The presence of a pi bond of an alkene or the ring of a cyclic compound decreases the number of hydrogen atoms in a molecular formula. These structural features are called __. Each __ corresponds to two fewer hydrogen atoms than in the __ formula.
- elements of unsaturation x2
How many levels of unsaturation in these:
a) one element of unsaturation (missing two Hydrogens)
b) two elements of unsaturation (missing four hydrogens
The number of elements of unsaturation is simply what?
half the number of missing hydrogens
__ are any atoms other than C and H. The rule for calculating elements of unsaturation in hydrocarbons can be extended to include __.
Halogens simply __ in the molecular formula.
What will you do if you encounter a halogen?
- substitute for hydrogen atoms
- count it as a hydrogen
An oxygen atom can be added to the chain without doing what?
When calculating the (EoS), what do you do?
- changing the number of hydrogen atoms or carbon atoms
- ignore the oxygen atoms
A nitrogen atom can take the place of a __ in the chain, but it is __, having only one additional H atom, compared with two hydroges for each additional carbon atom. In computing the elements of unsaturation, do what?
- count nitrogen as half a carbon atom
When the chain contains more than three carbon atoms, what occurs?
The chain is numbered starting from what?
a number is used to give the location of the double bond.
the end closest to the double bond, adn the double bond is given the lower number of its two double-bonded carbon atoms
Cycloalkenes are assumed to have the double bond in what?
the number one position
A compound with two double bonds is __; with three: __; with four: __. Numbers are used to specify the locations of the double bonds.
Alkenes named as substituents are called __. They can be named __ or by __. Common __ are the __, __, __, and __ groups.
The __ is different from the others because it is __ and does not undergo the typical reactions of alkenes.
- alkenyl groups
- common names
- alkenyl substituents
- phenyl x2