Organic Chem Flashcards
Where does the name carbon come from?
carbos meaning charcoal
Where is carbon most commonly found?
reserves of coal, oil and natural gas and all living matter
What are the three allotopic forms of carbon?
- amorphous (carbon black or soot)
- grpahite
- diamond
Carbon is a non-metallic element which makes up approximately 0.032% of Earth’s crust
What elements is organic chemistry based on?
carbon and several otther elements
What bonding does organic chemistry have?
all compounds are covalent
How many compounds are there in organic chemistry?
several million compounds
What is the flammability of organic chemicals?
most compounds are flammable
What is the solubilitty in water for organic chemicals?
most are insoluble in water (polar solvents)
most are soluble in organic (non-polar) solvents
What are the melting points of organic chemicals?
low. <300. degree celsius -> decompose on heating.
Organic chemicals are non electrolytes in solutions
and
reactions slow at 20 degree celsius
What is an organic family?
a group of organic compounds that have common structural arrangement. of atoms aclled a functional group
Members of the same organic family have similar physical and chemical properties due to the functional group
What is a functional group?
anything that is not single bonded to other carbons or hydrogens
what is the family of hydrocarbons?
organic compounds that ccontain only carbon and hydrogen atoms in their molecular structure
What is an alkane?
an organic moleccule with only carbon-carbon single bonds. and. carbon bonded to either carbon or hydrogen.
What do alkanes always end with?
ane
prefix meth
1
prefix eth
2
prefix prop
3
prefix but
4
prefix pent
5
prefix hex
6
prefix hept
7
prefix oct
8
prefix non
9
prefix dec
10
prefix undec
11
prefix dodec
12
What is the simplest. alkane?
CH4 -> methane
What is the general formula for alkanes?
CnH2n+2
What is the empirical moleccualr formula?
shows number and type of atoms present. No attempt to speccify structure.
What is the expanded moleccular formula?
shows groupings of atoms. Brackets indicate locations of branched chains
What is the structural formula?
gives a clear picture of all atoms and locations of bonds. Straigh lines represent chemical bonds between atoms. Although detailed and accurate, this method requires a lot of space
What is the condensed structural formula?
saves space. Carbon-hydron bonds are assumed to be present. Model shows all other bonds. Still specifies the location of branches
What is the line structural formula?
uses lines to represent chemical bonds. each end of straight line represents a carbon atom and each carbon is assumed to have as many hydrogen atoms bonded as neccessary
What are substituent groups?
side chains -> brances off of carbons, not part of the parent chain
What is the parent chain?
longest continuous chain or carbons
REMEMBER TO INDICATE WHEN THERE ARE MULTIPKLE SUBSTITUENT GROUPS
What is a cyclic alkane?
saturated ring structures
- add prefix cyclo
- generally shown as skeletal structures
ring always takes precedent unless the carbon chain is longer than the ring
What is an isomer?
molecules that have the same molecular formula but their atoms are in a different arrangement
constitional isomers = structural isomers
- molecules that have the same molecular formula but atoms bonded in a different sequence
- same chemical formula but different name
Are alkanes polar?
alkanes are non-polar
Are alkanes soluble in water?
no
Are alkanes soluble in benzene and other non-polar solvents?
yes
What is the boiling point for alkanes with 1-4 carbons? And examples of uses?
below 30 celsius -> gases: fuels to heatt and cook
What is the boiling point for alkanes with 5-16 carbons? and examples of uses?
30-265, liquids: automotic, diesel, jet engies, raw material for petrochemical
What is the boiling point for alkanes with 16-22 carbons? and examples of uses?
over 250 -> heavy liquids, oil furnaces and lubricatting oils
What is the boiling point for alkanes with 18+ carbons? and examples of uses?
over 400 -> semi solids: lubricating greases, paraffin waxes (candles, waxed paper and cosmetics)
What is the boiling point for alkanes with 26+ carbons? and examples of uses?
over 500 -> solid residues, asphalts, tars in paving and roofing industries
What is the reactivity of alkanes?
low reactivity because theirC-C bonds are stable and cannot be easily broken
alkanesalso called paraffins, which is latin means…
para + affinis = lacking affinity
Gaseous alkes are explosive when mixed with air
liquid alkanes are highly flammable, all alkanes react with oxygen in a combustion reaction
What is cracking?
the most imporant process for the commercial production of gasoline, breaks up heavy alkane. moleculesintothe lighter ones by means of heat and/or pressureand/or catalysts. It yields gasoline and gases such as methan, thane, ethylene, and propane
What is an alkyl Halide?
an organic compounds containing at least one carbon-halogen bond
What are some properties and examples of alkyl halides?
fire resistant solvents
refrigerants
pharmaceuticcals and precursors
What do you do if two halides or alkyl are equally distant from ends of chain?
begin at the end nearer the substituent whose name comes first in the alphabet
What is the solubility of haloalkanes?
only very slightly soluble in water
What are the boiling points of haloalkanes?
methyl halides are gases at room temp apart from iodomethane. (liquid)\
chloroethan is a gas, rest are liquids
Describe the chemical reactivity of haloalkanes
increase in reactivity as move down the group from chlorine to iodine because of the bond strength decreasing as move down group
What is an alchohol?
OH
hat are the bond angles of a hydroxyl atom?
approximately 109.5 dgrees -> the oxygen has two unshared pair of electrons
What takes precendence alchohols, alkanes, alkenes or halides?
alchohols.
alchohol
ane. ->a-#-ol
What is the naming if there are more than one alchohol?
diols, triols, etc
Are alchohols polar?
yes - the interact with themselves and with other polar compounds by dipole-dipole interactions
Ethanol and DImethyl ether are consitutional isomers. But have very different boiling points.
Why do ethanol and dimethyl ther have such different boiling points?
Ethanol forms intermolecular hydrogen bonds, which are attractive forces between its molecules, resulting in a higher boiling point. There is no comparable attractive force between molecules of dimethyl ether.
COmapre alchohols to alkanes of comparable size
alchohols have higher boiling points and are more soluble in water
(the presence of additional OH groups in a molecule further increases solubility in water and boiling point)
How do you name a carboxylic acid?
The e ending is removed from the name of the parent chain and is replaced with oic acid. Since a carboxylix acid group must always lie at the end of a carbon chain, it is always is given the #1 location position in numbering and it is not necessary to include it in the name.
What is an unsturated hydrocarbon?
A molecule that does not cntain the maximum number of hydrogen atoms
What is more reactive alkenes and alkynes or alkanes.
alkenes and alkynes
What is the simplest alkene?
ethen (ethylene) C2H4
What is the functional group of alkenes?
the carbon-carbon double bond
What is the functional group of alkynes?
the carbon-carbon triple bond
What is the simplest alkyne?
ethyne (acetylene) C2H2
What is the general formula for alkenes?
CnH2n
What the the suffic for alkenes?
-ene
What is the suffix for alkynes?
-yne
What do you do if an alkene or alkyne has more than one double bond?
2 double bonds = alkadiene
3 doubles bonds = alkatriene
Where must the double bond be on a cycloalkane?
between 1 and 2
What is the smallest cycloalkyne that is stable enough to be isolated?
cycloactyne - it is still very reactive though
Are alkenes polar?
no
Do alkenes dissolve in water?
no
What alkenes are gas a room temperature?
the first 3 - ethene, propene, and butene
How do the boiling points of alkenes comapre to alkanes?
alkenes have slightly lower boiling points
Any change in the location of double bond affects boiling point
Are alkynes polar?
no non-polar
What is the order or boiling points? Highest to Lowest
Alkynes, alkanes, alkenes
Explain the order of boiling points of alkanes, alkenes and alkynes.
Linear strucure of alkynes and nature of triple bond cause them to attract one another mroe strongly than alkanes and alkenes. Therefore takes more energy to overcome attractive forces.
Are alkenes and alkynes reactive?
Alkenes and alkynes are very reactive
How flammable and combustible are alkenes and alkynes?
highly flammable and combustible
What is the general formula for alkynes?
CnH2n-2
What is an isomer?
a molecule that has the same molecular formula, but a different arrangement of the atoms in space - it does not include different arrangements due to the molecule rotating
What is stereoisomers?
the atoms making up the isomers are joined up in the same order, but still manage to have a different spatial arrangement, gemetroc isomerism is one form of stereomerism. They occur where there are restricted rotation somewhere in a molecule like a carbon-carbon double bond.
molecules do not become isomers from twisting
If you have to take a model to pieces to convert it into another one, then it is an isomer.
When do you use the cis prefix in isomers?
if the substituents are on the same side of the double bond.
cis (latin meaning on this side)
When do you use the trans prefix in isomers?
when the substituents are on oppsite sides of the double bond
trans (from latin meaning across)
