Organic Chemistry Flashcards
An organic compound with 1 carbon atom has what prefix?
Meth
An organic compound with 2 carbon atoms has what prefix?
Eth
An organic compound with 3 carbon atoms has what prefix?
Prop
An organic compound with 4 carbon atoms has what prefix?
But
An organic compound with 5 carbon atoms has what prefix?
Pent
An organic compound with 6 carbon atoms has what prefix?
Hex
An organic compound with 7 carbon atoms has what prefix?
Hept
Define a carboxylic acid:
A compound containing the -COOH functional group and the general formula is: CNH2N+1COOH
Define a functional group:
The functional group is responsible for the characteristic chemical properties of a particular homologous series.
Define a homologous series:
A ‘family’ of similar compounds with similar chemical properties.
Same general formula.
Same functional group.
Same chemical properties.
Gradual trend in physical properties. .
Define a macromolecule:
A large molecule built up from small units called monomers.
define a saturated hydrocarbon?
It has no C-C multiple bonds (double bonds)
Define and describe an alkane:
A hydrocarbon which contains only single bonds. The general formula is: CNH2N+2.
Saturated hydrocarbon.
They are colourless componds.
Generally unreactive except for combusition, cracking and reaction with halogens in the prescence of ultravoilet light.
Burns with a blue flame which does not appear sooty.
Define an alcohol:
A compound contianing the -OH functional group and the general formula CNH2N+1OH
Define and alkene:
A hydrocarbon which contains one or more double bonds.
Define cracking?
The process by which large, less useful hydrocarbon molecules are broken down into smaller more useful alkanes and alkenes.
Define petroleum/crude oil:
A complex mixture of hydrocarbons in which some gases are dissvoled.
Do hydrocarbons with higher boiling points have longer or shorter chains than hydrocarbons with lower boiling points.
Hydrocarbons with shorter chains and lower mass have lower boiling points.
How do alkanes react with halogens?
Alkanes do not react with halogens in the dark.
In the prescence of sunlight / ultraviolet light a reaction does take place.
When 1 mol of chlorine reacts with one mol of mthane a chloirne atom relaces a hydrogen atom in the methane. This is called a substitution reaction.
CH4 + Cl2 = CH3Cl + HCl
Methane + chlorine = ? + Hydrochloric acid
In the presence of excess chlorine the hydrogen atoms are substituted one by one until there none left.
What are the products when alkenes combust?
The complete combustion of an alkene with oxygen produces CO2 and H20.
name 3 common products of fractional distillation?
in order of density:
natural gas
petrol/gasolene
naptha
kerosene
diesel
fuel oil
bitumen
Name the first 4 alkanes:
State a test for unsaturated compounds:
Aqueous bromine turns colourless when mixed with alkenes.
What are the 2 names for crude oil?
Crude oil and petroleum
What are the 3 common fossil fuels?
Coal - formed by decay of vegetation in the absence of oxygen millions of years ago. Natural gas - mainly methane. Hydrocarbons - such as methane, ethane, propane, obtained by fractional distillation of petroleum.
What are the 4 homologous groups called and what are their endings?
Alkanes - ane Alkenes - ene Alcohols - ol Carboxylic acids - oic acid
What are the names of the 3 different types of formulae?
Molecular formula Structural formula Condensed structural formula
what can be used to test between alkanes and alkenes?
aqueous bromine can be used.
bromine water reddish brown concentrated and orange when diluted.
bromine is added in the dark then:
alkanes: no change to colour of bromine water
alkenes: the bromine water becomes colourless
What are the products of this equation?
CH4 (g) + 2O2(g) =
CO2 (g) + 2H2O(l)
(also energy is produced - this is combustion).
What effect does a longer chain have on a hydrocarbon?
It changes the compound’s properties as it gets longer.
What happens in fractional distillation?
Different hydrocarbons have different boiling point ranges.
The fractionating column allows different hydrocarbons to be drawn off at different levels in the column.
Gases escape at the top.
Residue runs out at the bottom.
What happens when you crack an alkane?
The process called cracking is used to covert fractions containing larger less useful hydrocarbons into smaller more useful hydrocarbons.
Kerosene and diesel oil are often cracked to make more gaseoline, more alkanes or hydrogen.
Cracking is a from of decomposition.
What is a hydrocarbon?
A compound containing ONLY carbon and hydrogen atoms.
What is a Structural Isomer?
Compounds with the same molecular formula but different structural formula.
What is equation for combustion?
hydrocarbon + oxygen = CO2 + water (+energy)
What is the reaction betweeen an alkene and bromine?
Most reactions of alkenes are addtion reactions, this is where 2 molecules combine to make a single product.
Alkanes react with halogens to form dihalogenoalkanes. The hallogen adds across the double bond and no other product is formed.
Bromine reacts with ethene to form 1,2-dibromoethane.
what is produced when alkanes undergo incomplete combustion ?
Carbon monxide CO is produced and water.
What is the formula for ethane?
C2H6
What is the formula for propanoic acid?
CH₃CH₂CO₂H
What is the formula for propene?
C3H6
What is the formula for propane?
C3H8
or
CH3CH2CH3
What is the main constituent of natural gas?
Methane.
What is the molecular formula for ethanoic acid:
CH3COOH
What is the molecular formula for ethanol:
C2H5OH
What is the molecular formula for methane:
CH4
What is the molecular formula for butanoic acid:
C3H7COOH
what is the other name for petrol?
gasolene
What is the process called fro refining petroleum/crude oil?
Fractional distillation.
what temperature is the petroleum in the fractionating column heated to?
400 degrees centigrade.
When does complete combustion occur?
When there is plenty of oxygen.
What is the formula for ethane?
CH3CH3
What is the formula for propane?
CH3CH2CH3
or
C3H8
What is the formula for butane?
CH3CH2CH2CH3
or
C4H10
What functional group does alcohols have?
OH
Waht are the last 2 letters on each compound in the alcohol functional group?
ol
Waht is the general formula for alcohol?
CNH2N+1OH
What are the first 4 alcohols called?
Methanol
Ethanol
Propanol
Butanol
What is the chemical formula for methanol?
CH3OH
What is the chemical formula for ethanol?
C2H5OH
What is the chemical formula for propanol?
C3H7OH
What is the chemical formula for butanol?
C4H9OH
Are alcohols flammable?
Yes.
Do alcohols undergo complete combution in air forming CO2 and H2O?
Yes.
What is the chemical equation for the combustion of alcohol (e.g. methanol)?
2CH3OH (l) + 3O2 (g) = 2CO2 (g) + 4H2O (g)
What PH value do the first 4 alcohols in soltion in water have?
Neutral.
Are alcohols soluable in water?
Yes
Can alcohols be oxidised?
Yes they can react with oxygen (form the air) to produce carboxylic acid.
e.g Methanol is oxidsed to methanoic acid
ethanol is oxidised to ethanoic acid
What can alcohols be used for?
As solvents (they dissolve everything that water can and hydrocarbons, oils and fats is addtion)
The first 4 alcohols can be used as fuels.
e.g. ethanol can be used in spirit burners. burns cleanly and is non smelly.
What is the natural process that alcohol can be made by?
Fermentation.
What is ethanol commonly found in?
wine and beer.
How does fermentation work?
It uses an enzyme in yeast to covert sugars into ethanol. CO2 is also produced (bubbles).
Sugar + yeast = ethanol + carbon dioxide
At what temperature does fermentation happen fastest at?
37 o C
(also best in a slightly acidic solution and anaerobic conditions (no oxygen)).
With different conditions the yeast (enzyme) could be destroyed/denatured or work at a much slower rate.
Do alcohols react with sodium?
Yes.
One of the products of he reaction is hydrogen.
