Topic 13 - Intro to Organic Chemistry Flashcards
What is the general formula?
An algebraic formula that can be applied to chemicals in the ‘family’. e.g. alkenes, alkanes, alcohols, etc
What is the general formula for alkanes?
CnH2n + 2
What is the general formula for alkenes?
CnH2n
What is the general formula for alcohols?
CnH(2n + 1)OH
What is the molecular formula?
The actual number of atoms in a molecule or element.
What is the empirical formula?
Simplest whole number ratio of atoms in a compound.
What is the structural formula?
The arrangement of atoms in a molecule without showing all the bonds.
What is the skeletal formula?
Shows the bonds of a carbon skeleton formula. Hydrogen and carbon atoms not shown but functional groups are.
What is the displayed formula?
Shows the arrangement of atoms showing all the bonds and atoms in a molecule.
What is a homologous series?
A group of compounds that have the same general formula and functional group.
What are the two types of bond fission?
Homolytic and heterolytic.
What is bond fission?
The breaking of a covalent bond.
What is heterolytic fission?
The bond breaks but the electrons are distributed unequally forming 2 ions (an anion and a cation).
What sort of arrow shows heterolytic fission?
Double-headed arrow.
What is homolytic fission?
The bond breaks equally forming 2 uncharged radicals.
What sort of arrow shows homolytic fission?
Single-headed arrow.
What symbolizes free radicals?
A dot for an unpaired electron.
What are the 3 stages for free radical reactions?
Initiation, Propagation, Termination.
What sort of reaction makes halogenoalkanes?
Free radical substitution.
What are the 7 types of reactions?
Addition
Substitution
Elimination/Dehydration
Condensation
Hydrolysis
Oxidation
Reduction
What is an addition reaction?
A double bond is broken and two molecules join to form a single product.
What is a substitution reaction?
A functional group is exchanged for another one.
What is an elimination/dehydration reaction?
A double bond is normally formed when a functional group is removed and released as part of a smaller molecule.
What is a condensation reaction?
When 2 molecules join and a small molecule is eliminated (usually water).
What is a hydrolysis reaction
2 smaller molecules are formed by splitting a larger one with water.
What is an oxidation reaction?
Gain of oxygen or loss of hydrogen or loss of electrons.
What is a reduction reaction?
Loss of oxygen or gain of hydrogen or gain of electron.
What are the three types of attacking agents?
Electrophiles, nucleophiles, and radicals.
What are electrophiles?
Electron loving species that are generally positively charged ions. They attack other molecules with a negative charge or a delta negative charge.
What are 7 examples of electrophiles?
H+ , Cl+/Br+/I+ , CH3+ , NO2+ , CH3CO+
What are nucleophiles?
Nucleus loving species that must have a lone pair of electrons and some have a negative charge. They attack molecules with a positive charge or a delta positive charge.
What are 4 examples of nucleophiles?
OH- , NH3 , H2O , CN-
What are radicals?
Atoms with an unpaired electron that are very reactive. Initially formed via UV light.
What are 3 examples of radicals?
Cl* , CH3* , Br*
What are the two types of bonds in covalent molecules?
sigma and pi bonds.
What are sigma bonds?
When two orbitals overlap.
What type of bonds does a double bond contain?
A sigma bond and a pi bond.
What are pi bonds?
The parallel overlap of two p orbitals.
What are structural isomers?
Isomers that have the same molecular formula but a different structural formula.
What are the three types of structural isomers?
- Chain
- Positional
- Functional group
What are chain isomers?
Same molecular formula but a different arrangement of the carbon skeleton.
What are positional isomers?
Same molecular formula but different position of the functional group on the carbon skeleton.
What are functional group isomers?
Same molecular formula but different functional group.
What are stereoisomers?
The same structural formula but a different arrangement of atoms in space.
What are the two types of stereoisomers?
Cis/trans isomers.
Optical isomers.
What sort of bond is needed for cis/trans isomerism?
C=C double bond
When do you get cis/trans isomerism?
When there are two different atoms or groups of atoms on the same carbon.
What are cis isomers?
Where the same groups are on the same side of the double bond.
What are trans isomers?
Where the same groups are opposite the double bond.
What does cis mean?
Same.
What does trans mean?
Different.
What do they mean by ‘same side of the double bond’?
Both above the double bond or both below the double bond.
What is another name for cis/trans isomers?
Z - same side
E - opposite side
What are optical isomers?
Mirror images of each other that have a chiral carbon atom.
What is a chiral molecule?
When there are 4 different groups coming off the carbon.
What are enantiomers?
The 2 different molecules formed from arranging the groups on a chiral carbon in 2 different ways.
What do enantiomers look like?
They are mirror images of each other.
Are enantiomers superimposable?
No
How do you find the chiral centre?
Draw them in a tetrahedral 3D shape to show them as enantiomers.
Can molecules have more than one chiral centre?
Yes
How many chiral centres does ascorbic acid (Vitamin C) have?
2
