chem exam flashcards

Alkane

Hydrocarbons with single bonds (saturated).

Alkene

Hydrocarbons with one or more double bonds (unsaturated).

Alkyne

Hydrocarbons with one or more triple bonds (unsaturated).

Aliphatic hydrocarbons

Hydrocarbons in straight chains.

Cyclic hydrocarbons

Hydrocarbons arranged in rings.

Aromatic hydrocarbons

Hydrocarbons containing a benzene ring.

Structural shorthand in organic chemistry

Represents carbon atoms as line intersections and omits hydrogen atoms attached to carbon.

Root names for hydrocarbons with 1 carbon

meth-.

Root names for hydrocarbons with 2 carbons

eth-.

Root names for hydrocarbons with 3 carbons

prop-.

Root names for hydrocarbons with 4 carbons

but-.

Root names for hydrocarbons with 5-10 carbons

pent-, hex-, hept-, oct-, non-, dec-.

Alkane naming rule

Longest carbon chain + root + -ane.

Branch naming in alkanes

Branches are named alkyl groups and labeled -yl.

Position numbering in alkanes

Number the carbon chain to give lowest numbers to branches.

Multiple branches in alkane naming

Use di-, tri-, tetra-, etc., without affecting alphabetical order.

Punctuation rules in naming alkanes

Commas between numbers, hyphens between numbers and letters.

Example of alkane

2-methylbutane.

Example of branched alkane

2-chloro-3,6-dimethylnonane.

Cycloalkanes

Cyclic alkanes use the prefix 'cyclo-' + root + -ane.

Haloalkanes

Alkanes with halogens, named as fluoro, chloro, bromo, iodo.

Line-angle representation

Each vertex or endpoint represents a carbon atom, hydrogen atoms are usually omitted.

Naming alkenes and alkynes

Identify longest carbon chain with double/triple bond, indicate bond position.

Suffix for alkenes

-ene.

Suffix for alkynes

-yne.

Prefix for rings in cyclic hydrocarbons

cyclo-.

Functional group of alcohol

–OH (hydroxyl group).

Primary alcohol

–OH attached to a carbon with one other carbon.

Secondary alcohol

–OH attached to a carbon with two other carbons.

Tertiary alcohol

–OH attached to a carbon with three other carbons.

Naming alcohols

Replace -e of alkane with -ol, using lowest positions for -OH.

Properties of alcohols

Alcohols are polar, can form hydrogen bonds, and have higher boiling points than comparable alkanes.

Identifying primary, secondary, or tertiary alcohols

Count the number of carbons attached to the carbon with –OH.

Functional groups overview

Different organic compounds characterized by specific groups, e.g., alkane, alkene, alcohol.

Hydrogen bonding

Strong intermolecular force present in alcohols due to –OH.

Types of isomers

Structural isomers have the same molecular formula but different arrangements.

Geometric isomers

Isomers that differ in the arrangement of groups around a double bond (cis/trans).

Cis isomer

Larger groups on the same side of a double bond.

Trans isomer

Larger groups on opposite sides of a double bond.

Boiling point trend for hydrocarbons

Boiling point increases with size and surface area.

Combustion reaction of alkanes

Alkanes react with oxygen to produce CO₂ and H₂O.

Substitution reaction in haloalkanes

Halogens replace hydrogen in alkanes/alkenes.

Addition reactions in alkenes

Alkenes can undergo hydrogenation, halogenation, hydrohalogenation.

Polarity of hydrocarbons

Hydrocarbons tend to be non-polar due to symmetrical structures.

Solubility of hydrocarbons

Hydrocarbons are generally insoluble in water.

Factors affecting boiling points of compounds

Higher molecular weight and increased surface area lead to higher boiling points.

Octet rule

Atoms tend to have eight electrons in their valence shell when bonded.

Covalent bonds

Bonds formed by sharing electrons between non-metal atoms.

Ionic bonds

Bonds formed by the transfer of electrons between metals and non-metals.

Lewis structures

Diagrams that represent the bonding between atoms and the lone pairs of electrons.

VSEPR theory

Models the geometry of molecular structures based on electron pair repulsions.

Bond order

The number of shared electron pairs between atoms; higher bond order means stronger bond.

Resonance structures

Different valid Lewis structures for the same molecule due to electron delocalization.

Hydrogen bonding in alcohols

Significant interaction that raises boiling points.

Types of chemical equilibrium

Solubility, phase, and chemical reaction equilibria.

Factors influencing solubility

Polarity, intermolecular forces, and molecular size.

Percent reaction at equilibrium

Determines yield of products compared to maximum theoretical amount.

Types of polymers

Natural and synthetic polymers created through polymerization processes.

Cis-2-butene

Geometric isomer with both larger groups on the same side of the double bond.

Trans-2-butene

Geometric isomer with larger groups on opposite sides of the double bond.

Lewis dot structure example for H₂O

Shows oxygen in the center bonded to hydrogen atoms with lone pairs.

Markovnikov's Rule

In addition reactions of alkenes, the H atom adds to the carbon with more hydrogens.

Hydrogenation of aldehydes/ketones

Converts aldehydes/ketones to alcohols by adding hydrogen.

Chemical property of alkenes

Alkenes are reactive due to the presence of double bonds.

Intermolecular forces description

Forces present between molecules affecting physical properties.

Phase equilibrium example

The balance between solid and liquid states of a substance.

Dynamic equilibrium

When the rates of forward and reverse processes are equal.

Equilibrium constant (K)

Expresses the ratio of products to reactants at equilibrium, excluding solids/liquids.

Heterogeneous equilibrium

Equilibrium with species in different phases.

Homogeneous equilibrium

Equilibrium with all species in the same phase.

Percent reaction favoring products

A high percentage indicates that the forward reaction predominates.

Acid-base equilibrium

Describes reactions where acids and bases react to form conjugate pairs.

Role of catalysts

Substances that speed up reactions without being consumed.

Chemical kinetics overview

The study of reaction rates and the factors affecting them.

Rate law expression

Describes how the rate of a reaction depends on the concentration of reactants.

Activation energy

The minimum energy required for a reaction to occur.

Rate constant (k)

A proportionality constant in the rate law equation.

Arrhenius equation

Describes how the rate constant depends on temperature and activation energy.

Dynamic processes in chemistry

Reactions occur continuously, but observable changes may not be apparent.

Factors affecting reaction rates

Concentration, temperature, catalysts, and surface area.

Thermodynamics in chemical reactions

Study of energy changes in chemical processes.

Enthalpy of formation

The change in heat during the creation of a compound from its elements.

Entropy (S)

A measure of disorder or randomness in a system.