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55 Cards in this Set
- Front
- Back
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What are hydrocarbons?
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compounds whose molecules contain only carbon and hydrogen atoms.
eg. methane (CH4) and ethane (C2H6) |
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What are alkanes?
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hydrocarbons whose members do not have multiple bonds between carbon atoms
eg. methane, butane |
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What are alkenes?
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hydrocarbons whose molecules have a carbon-carbon double bond
eg. ethene and propene |
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What are alkynes?
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hydrocarbons whose molecules have a carbon-carbon triple bond
(eg. ethyne) |
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What are aromatic hydrocarbons?
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hydrocarbons that contain a special ring
(eg. benzene) |
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What are saturated compounds?
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compounds that contain the maximum number of hydrogen atoms that the carbon compound can possess
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What are unsaturated compounds?
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compounds that contain fewer than the maximum number of hydrogen atoms
eg. compounds with multiple bonds, such as alkenes, alkynes, and aromatic hydrocarbons |
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What is electronegativity?
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the ability of an element to attract electrons that is sharing in a covalent bond
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What are polar covalent bonds?
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bonds between atoms of different electronegativity values
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What is a dipole?
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a molecule with with a partially positive end and a partially negative end
eg. hydrogen chloride - hydrogen has a partially positive charge, and chlorine has a partially negative charge because it is more electronegative than hydrogen |
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What is the equation for dipole moment?
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dipole moment = charge (in esu) x distance (in cm)
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What is a polar molecule?
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molecule with a dipole moment; two different atoms with different electronegativities
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Why is CCl4 polar even though it has no dipole moment?
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Because the electronegativity of chlorine is greater than that of carbon, each chlorine atom has a partial negative charge, and the carbon atom is considerably positive. Since this molecule is tetrahedral, the center of positive charge and the center of negative charge coincide, and the molecule has no net dipole moment
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What is a functional group?
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the part of a molecule where most of its chemical reactions occur
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Methane
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CH4
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ethane
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CH3CH3
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propane
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CH3CH2CH3
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How is the propyl group derived?
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Removal of a hydrogen from one of the end carbon atoms of propane.
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How is the isopropyl group derived?
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Removal of a hydrogen from the middle carbon atom of propane.
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What is the symbol R?
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general symbol to represent any alkyl group
(eg. methyl, ehtyl, propyl, and isopropyl can all be designated by R) |
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What is a phenyl group?
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a benzene ring attached to some other group of atoms in a molecule
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What is a benzyl group?
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the combination of a phenyl group and a methylene group (-CH2-)
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What are haloalkanes?
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compounds in which a halogen atom (F, Cl, Br, I) replaces a hydrogen atom of an alkane
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What is a primary alkyl halide?
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alkyl halide in which the carbon atom to which the halogen is attached to is only attached to one other carbon atom
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What is a secondadry alkyl halide?
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alkyl halide in which the carbon atom to which the halogen is attached to is attached to two other carbon atoms
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What characterizes an alcohol?
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the hydroxyl (OH) group attached to an sp3-hybridized carbon atom
eg. methyl alcohol (methanol) and ethyl alcohol (ethanol) |
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What are the two ways that alcohols can be viewed structurally?
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(1) as hydroxyl derivatives of alkanes
(2) as alkyl derivatives of water |
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How are alcohols classified?
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primary - if the carbon attached to the OH group has only one other carbon attached to it
seconday, tertiary |
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What is the general formula of ethers?
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R-O-R or R-O-R'
R' may be an alkyl (or phenyl) group different from R. Can be viewed as derivatives of water in which both hydrogen atoms have been replaced by alkyl groups |
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What are amines?
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can be seen as organic derivates of ammonia (NH3)
R - N - H | H |
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How are amines classified?
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Primary, secondary, or tertiary amines. Based on the number of organic groups that are attached to the nitrogen atom.
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What is a carbonyl group?
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a group in which a carbon atom has a double bond to oxygen
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Describe an aldehyde?
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the carbonyl group of an aldehyde is bonded to one hydrogen atom and one carbon atom
RCHO |
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Describe a ketone
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the carbonyl grouop of a ketone is bonded to two carbon atoms
RCOR' |
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What is the only aldehyde that differs from the standard structure?
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formaldehyde is the only aldehyde that has two hydrogen atoms
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Describe the arrangement of aldehydes and ketones.
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they have a trigonal planar arrangement of groups around the carbonyl carbon atom.
the carbon atom is sp2 hybridized |
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What is a carboxylic acid?
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a carbonyl group bonded to a hydroxyl group
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What is the general formula of a carboxylic aicd?
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RCO2H
eg. formic acid, acetic acide, and benzoic acid |
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What is the general formula of a carboxyl group?
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-CO2H or -COOH
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What is an ester?
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have a general formula of RCO2R' (or RCOOR'), where a carbonyl group is bonded to an alkoxyl (-OR) group
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How can esters be made from a carboxylic acid and an alcohol?
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through the acid-catalyzed loss of a molecule of water
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What are the formulas for amides?
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RCONH2
RCONHR' RCONR'R" |
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Describe the structure of an amide?
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A carbonyl group bonded to a nitrogen atom bearing hydrogen and/or alkyl groups
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What is the general formula of a nitrile?
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R-CN
in which there is a triple bond between carbon and nitrogen |
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What is melting point?
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the temperature at which an equilibirium exists between the well-ordered crystalline state and the more random liquid state
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Describe the melting and boiling points of ionic compounds.
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They have very high melting and boiling points because of their strong ion-ion forces.
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Why are most organic molecules not fully ionic?
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Because instead they have a permanent dipole moment resulting from a nonuniform distribution of the bonding electrons.
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What is a dipole-dipole attraction?
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they cause the molecules in the liquid or solid state to orient themselves so that the positive end of one molecule is directed toward the negative end of another
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What is a hydrogen bond?
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a strong dipole-dipole interaction that occurs between hydrogen atoms bonded to small strongly electronegative atoms (O, N, or F) and the nonbonding electron pairs on other such electronegative atoms
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What are some factors that affect melting point of organic compounds?
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polarity, hydrogen bonding, the compactness and rigidity of their inidividual molecules
Molecules that are symmetrical generally have abnormally high melting points. |
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What are van der Waals forces?
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Weak forces that act between nonpolar molecules or between parts of the same molecule.
Bringing two groups or molecules together first results in an attractive force between them because a temporary unsymmetrical distribution of electrons in one group induces an opposite polarity in the other. |
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What is polarizability?
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the ability of the electrons to respond to a changing electric field
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What are the general solubility rules?
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"like dissolves like" Polar and ionic compounds tend to dissolve in polar solvents. Nonpolar solids are usually soluble in nonpolar solvents.
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Why are nonpolar groups such as long alkane chains hydrophobic?
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Because this involves an unfavorable entropy change. For a nonpolar hydrocarbon chain to be accommodated by water, the water molecules have to form a more ordered structure around the chain. and this entropy is unfavorable.
(changes from order to disorder are favorable) |
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What are the general guidelines for water solubility for compounds containing one hydrophilic group?
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Compounds with one to three carbon atoms are water soluble, compounds with four or five carbon atoms are borderline, and compounds with six or more carbon atoms are insoluble.
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