Organic Chemistry Flashcards
Describe organic molecules
Molecules containing carbon atoms with the exception of carbon dioxide, carbon monoxide, diamond, graphite, carbonates, carbides and cyanides
Hydrocarbon
A compound containing on,y carbon and hydrogen atoms
Saturated compound
A compound in which all of the bonds between carbon atoms are single bonds
Unsaturated compound
A compound in which there is at least one double and/or triple bond between carbon atoms
Functional group
an atom or a group of atoms that form the centre of chemical activity in the molecule
Homologous series
a series of similar compounds which have the same functional group and have the same general formula, in which each member differs from the previous one by a single CH2 unit
What is the functional group of alkanes?
Only C-H and C-C bonds
What is the functional group of alkenes?
Carbon-carbon double bond
What is the functional group of haloalkanes?
Halogen atom bonded to a saturated C atom
What is the functional group of alcohols?
Hydroxyl group bonded to a saturated C atom
What is the functional group of carboxylic acids?
Carboxyl group
What is the functional group of esters?
Ester group
Describe a structural formula
Atoms are represented by their chemical symbols and lines are used to represent all the bonds between atoms.
Describe a condensed structural formula
Represents the way in which atoms are bonded, but NOT ALL bond lines are shown.
Describe a molecular formula
This is a chemical formula that indicates the type of atoms and the correct number of each in a molecule.
Structural isomers
compounds having the same molecular formula but different structural formulae
Describe chain isomers
Different type of chain structure, i.e. branching
Describe positional isomers
Different positions of the same functional group or alkyl substituent on the parent chain
Describe functional isomers
Different functional groups
What is the intermolecular force of all hydrocarbon molecules
London intermolecular forces (molecules are non-polar)
Why is a water bath used for gentle heating of organic reaction mixtures?
Many organic compounds are flammable
What type of reaction is a combustion reaction?
Exothermic
What are the general reaction types?
- combustion
- substitution
- addition
- elimination
- esterification
What are the specific types of substitution reactions?
- Halogenation
- hydrolysis
What is the conversion and reaction conditions for Halogenation (substitution)?
Conversion: alkanes to haloalkanes
Reaction condition: in the presence of ultraviolet light or heat)
What is the conversion and reaction conditions for Hydrolysis (substitution)?
Conversion: haloalkanes to alcohols
Reaction conditions: heat under reflux in a dilute aqueous alkali solution
If the reaction condition is “in the presence of ultraviolet light or heat”, what is the specific reaction?
Halogenation (substitution)
If the reaction condition is “heat under reflux in a dilute aqueous alkali solution”, what is the specific reaction?
Hydrolysis
What are the specific types of addition reactions?
- hydrogenation
- Halogenation
-hydrohalogenation - hydration
What are the specific types of elimination reactions?
- dehydrohalogenation
- dehydration
- cracking of hydrocarbons
What is the conversion and reaction conditions for Halogenation (addition)?
Conversion: addition of a Halogen (X2; X = Cl, Br)
Reaction conditions: test for unsaturation
What is the conversion and reaction conditions for Hydration (addition)?
Conversion: addition of H2O to any alkene
Reaction condition: steam and a suitable catalyst)
What is the conversion and reaction conditions for Hydrogenation (addition)?
Conversion: addition of H2 to any alkene
Reaction condition: alkene dissolved in an organic solvent with a Pt, Pd or Ni caltalyst in a H2 atmosphere
What is the conversion and reaction conditions for Hydrohalogenation (addition)?
Conversion: addition of HX to any alkene ( X = halogen)
Reaction condition: no water may be present
What is the test for unsaturation?
The rapid decolonisation of bromine water by an alkene at room temperature
What is the purpose of the test for unsaturation?
To distinguish an alkene from an alkene (difference in Halogenation reactions)
How is the the test for unsaturation able to distinguish alkenes from alkanes?
Since alkenes are more reactive than alkanes, addition reactions occur faster than substitution reactions
If the reaction condition is “alkene dissolved in an organic solvent with a Pt, Pd or Ni catalyst in a H2 atmosphere “, what is the specific reaction?
Hydrogenation
If the reaction condition is “test for unsaturation”, what is the specific reaction?
Halogenation (addition)
If the reaction condition is “no water may be present”, what is the specific reaction?
Hydrohalogenation
If the reaction condition is “steam and a suitable catalyst”, what is the specific reaction?
Hydration
What is the conversion and reaction conditions for dehydrohalogenation (elimination)?
Conversion: elimination of HX from any haloalkane (X = halogen)
Reaction condition : hot concentrated solution of NaOH or KOH in an ethanol solvent ie. in the absence of water; the amount of water produced in the second reaction is insufficient to cause hydrolysis
What is the conversion and reaction conditions of dehydration (elimination)?
Conversion: elimination of H2O from any alcohol
Reaction conditions: acid catalysed dehydration- heating of alcohol with an excess of concentrated H2SO4 or H3PO4
If the reaction condition is “hot concentrated solution of NaOH or KOH in an ethanol solvent”, what is the specific reaction?
Dehydrohalogenation
If the reaction condition is “heating of alcohol with an excess of concentrated H2SO4 or H3PO4”, what is the specific reaction?
Dehydration
What is the cracking of hydrocarbons?
Breaking up large alkane molecules to form a mixture of smaller and more useful alkane and alkene molecules
What are the reaction conditions for the cracking of hydrocarbons?
- thermal cracking : high pressures and temperatures without a catalyst
- catalytic cracking : lower temperatures and pressures in the presence of a catalyst
Are combustion reactions exothermic or endothermic?
Exothermic
What is esterification?
An acid-catalysed reaction between an alcohol and a carboxylic acid that produces an ester and water
What are the reaction conditions for esterification?
Acid catalyst and gentle heating
What are two known products of the complete combustion of alkanes, alkenes and alcohols with excess oxygen?
Produce water (H2O) and carbon dioxide (CO2)