Organic Chem Test 1 Review

What are some physical properties of alkenes and alkynes?

Alkenes/kynes are non polar; insoluble in water; soluble in non polar organic solvents; less dense than water -Flammable, nontoxic UNLIKE ALKANES: Alkenes have cis-trans. Kenes/kynes are chemically reactive at the multiple bond.

What is Markovnikov's rule?

In the addition of HX to an alkene, the H attaches to the carbon that already has the most H's and the X attaches to the carbon that has fewer H's

What are substituents?

An atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon.

What are alkynes?

A hydrocarbon that contains a C to C triple bond.

What are alkenes?

A hydrocarbon that contains a C=C double bond; petrochemicals in the petroleum industry

What is an arene?

Another name for "aromatic"

What's the structure rule for alkenes?

CnH2n

What is a combustion reaction?

A chemical reaction that produces a flame, usually because of burning with oxygen. CO2 and H2O are products of complete combustion of any hydrocarbon, and a large amount of heat is released. Incomplete combustion yields CO and H2O.

What is a mechanism for a reaction?

A description of the individual steps by which old bonds are broken and new bonds are formed in a reaction

What are cycloalkenes?

A family of hydrocarbons which exist in a ring with a double bond somewhere in the ring.

What are functional groups?

A group of atoms within a larger molecule that has a characteristic structure and chemical behavior. The chemistry of an organic molecule is primarily determined not by its size and complexity, but by the functional groups it contains. A given functional group tends to undergo the same reactions in every molecule of which it is a part.

What is a saturated hydrocarbon?

A hydrocarbon that contains only single bonds- all bonding positions are occupied (ex: ethane)

What do we mean by cis-trans isomerism?

A type of isomerism which deals with the orientation of the branches in space (or their orientation above or below the plane) Cis is both are the same (both above or both below), trans is opposite

Are alkanes saturated or unsaturated?

Saturated; alkenes and alkynes are unsaturated (if it contains a C to C multiple bond)

What is the difference between straight-chain and branched chain alkanes?

Straight chain= alkane that has all its carbons connected in a row Branched= alkane that has a branching connection of carbons

What are aromatic compounds?

The class of compounds containing benzene-like rings. Benzene and other aromatic compounds are much less reactive than alkenes. Reacts by substitution like an alkane.

What happens during this type of reaction?

Alkenes react with HBr to yield alkyl bromides and with hydrogen chloride (HCl) to yield alkyl chlorides in what are called hydrohalogenation reactions "Birds of a feather flock together"

What is true about carbon compounds?

-Carbon is tetravalent-alwyas forms 4 bonds -Covalent bonds

Aromatic compounds with 2 substituents?

-Disubstituated aromatic compounds are named using one of the prefixes ortho-, meta-, or para- -An ortho or o-disubstituted benzene has its 2 substituents in a 1,2 relationship on the ring. -A meta- has 1,3 A para- has 1, 4

What are some properties of alkanes?

-Odorless or mild, colorless, tasteless, nontoxic -Nonpolar; insoluble in water but soluble in non polar organic solvents; less dense than H2O -Flammable, but otherwise not very reactive -1st 4 alkanes are gases @room temp and pressure, alkanes w/ 5-15 carbons are usually liquids. 16 or more are low-melting, waxy solids -As chain link increases, boiling point increases -More branches for same # of carbons= lowers boiling point

How do we name cycloalkanes?

1. Use the cycloalkane name as the parent. If there's just 1 substituent, no number group 2. Identify and number the substituents. Start at alphabetical priority, second substituent the lower possible #

What are the rules for naming alkanes using IUPAC?

1. Name the main chain (longest chain of C, name according to # of carbon atoms) 2. Number carbon atoms in the main chain. Begin at the end near the 1st branch. 3. Identify the branching substituents, and number each according to its point of attachment to the main chain 4. Write the name as a single world using hyphens to separate the #s from the different prefixes and commas to separate #s if necessary. Alphabetical order. If 2 or more identical substituents are present use di, tri, tetra- etc.

How do we name alkenes using IUPAC?

1. Name the parent compound (and add -ene or -yne); longest chain containing the double/triple bond 2. Number the carbon atoms in the main chain, beginning at the end near the multiple bond (unless it's equidistant, then to the branch!) 3. Write the full name. Assign #s to branching substituents, list them alphabetically. Commas separate words from #s. indicate position of multiple bond in chain by giving the # of the 1st one

How do we name alkynes?

Change the name of the parent chain with a "yne" ending. Number the location of the triple bond.

What are hydrocarbons?

Compound that has hydrogen and carbon

What are constitutional isomers?

Compounds with the same molecular formula but different connections among their atoms. KNOW: # of possible isomers grows rapidly as # of C atoms increase Different ci's are completely different chemical compounds with diff. structures, physical/physiological properties

What are cycloalkanes?

Contain a ring of carbon atoms; cyclopentane would be more reactive than a bigger, more stable ring

How do we draw a line-angle formula for alkanes?

Each point on the line represents a carbon atom-- hydrogens are not shown

What are conformers?

Identical compounds with identical structures/connections

What are conformations?

Infinite # of possible 3-dimensional geometries/alignments

What are stereoisomers?

Isomers which differ only by their orientation in space

What is a resonance hybrid?

One of the resonance structures

What are alkanes?

Only single bonds; all are saturated

What is the IUPAC system of nomenclature?

Organized system of rules for naming organic compounds. Chemical name has 3 parts: prefix, parent, and suffix. Prefix= substituents, parent=carbons, suffix= is family molecule belongs to

What is a primary, secondary, tertiary, and quaternary carbons?

Primary- 1 other carbon attached (1º) Secondary- 2 other carbons (2º) Tertiary- 3º Quaternary- 4º

What is the difference between complete and incomplete combustion?

Products (CO2 and water vs. CO and water)

What do we mean by an addition reaction?

Reaction type in which a substance X-Y adds to the multiple bond of an unsaturated reactant to yield a saturated product that has only single bonds.

What are aliphatic hydrocarbons?

Straight-chain hydrocarbons (vs. rings or branched chains)

How do we name aromatic compounds with one substituent?

Substituted benzene are named using -benzene as the parent No number is needed for mono substituted benzenes because all the ring positions are identical

What is nitration?

Substitution of a hydrogen atom on the benzene ring for a nitro group (NO2)

What is halogenation?

The addition of Cl2 or Br2 to a multiple bond to give a dihalide product. Substitution reaction where a H on the benzene ring is substituted with a halogen.

What is catalytic hydrogenation?

The addition of H2 to a multiple bond to give a saturated product. Alkenes and alkynes react with hydrogen in the presence of a metal catalyst to yield the corresponding alkane product.

What is hydration?

The addition of water, in the presence of a strong acid catalyst, to a multiple bond to give an alcohol product

What are alkyl groups?

The part of an alkane that remains when a hydrogen atom is removed

What is organic chemistry?

The study of carbon compounds

What is resonance?

True structure of a molecule is in average among 2 or more possible conventional structures, and a special double-headed arrow

What do we mean by cis-trans isomerism in alkenes?

We mean that certain groups will be oriented across the double bond above or below the plane.

What are condensed structures?

Writing the formula of the alkane with symbols. (ex: -c-c-c-c-= CH3CH2CH2CH3)

Aromatic compounds with 3 or more substituents?

You number the substituents and list them alphabetically. For ex: 1,2-dichloro-3-fluorobenzene