Organic Chemistry Flashcards
Mainly CGP
What is an organic compound?
Chemical compounds that contain Carbon (C)
What elements are common in many organic compounds?
- (Carbon)
- Hydrogen
- Oxygen
- Nitrogen
- Chlorine
What is a general formula?
An algebraic formula that can be used to find the formula of any compound in a homologous series.
Give an example of a general formula:
Cn H2n+2 - Alkanes
What is an empirical formula?
The simplest whole number ratio of atoms of each element in a compound.
Give an example of an empirical formula:
CH2
What is the molecular formula?
The actual number of atoms of each element in a compound.
What is the displayed formula?
Shows how all atoms are arranged, and all the bonds between them.
What is the structural formula?
Shows the arrangement of atoms carbon-by-carbon, with the attached hydrogen’s/functional groups.
Give an example of an structural formula:
CH2CH2
Give an example of an molecular formula:
C2H4
What is a Homologous Series?
A group of compounds that can be represented by the same general formula.
Give an example of a Homologous Series:
Alkenes - Cn H2n
What can the general formula be used to find?
The molecular formula (and empirical) formula of any member of a homologous series.
What is a Functional Group?
A group of atoms that determine how a compound typically reacts.
Compounds in a homologous series often ______?
react in similar ways.
Molecules in a homologous series contain the same _____?
functional group.
What is Nomenclature?
A fancy word for the naming of organic compounds.
What is the IUPAC system?
A international system created to name organic compounds.
IUPAC name for
1 carbon?
Meth-
IUPAC name for
2 carbons?
Eth-
IUPAC name for
3 carbons?
Prop-
IUPAC name for
4 carbons?
But-
IUPAC name for
5 carbons?
Pent-
IUPAC name for
6 carbons?
Hex-
What are the main functional groups?
Alkane Alkene Alcohol Carboxylic Acids Esters
What word is given for 2 identical functional groups?
di-
What word is given for 3 identical functional groups?
tri-
What word is given for 4 identical functional groups?
tetra-
(IUPAC) Suffix for Alkanes?
-ane
(IUPAC) Suffix for Alkenes?
-ene
(IUPAC) Suffix for Alcohols?
-ol
(IUPAC) Suffix for Carboxylic acids?
-oic acid
(IUPAC) Suffix for Esters?
-anoate
(IUPAC) Prefix for Esters?
alkyl (-yl)
In Organic Chemistry, what is an isomer?
Two molecules that have the same molecular structure, but different structural formula’s, (or atom arrangements).
What could make a molecule an isomer?
- Different carbon arrangements ( are they straight-chain or branched?)
- Arrangement of functional groups ( are they attached to middle or ends?)
- Different functional groups ( are they both in the same functional group?)
True/False
All Isomers have similar chemical properties?
False - Though many do, as they still have the same molecular formula. However, isomers with different functional groups will behave vastly differently.
Isomers have different physical properties, such as boiling points, explain why?
They have different molecular shapes, so bonds are different.
What formed crude oil over millions of years ago?
High temperatures and pressures caused the buried remains of plant and animal matter to turn into crude oil.
Put simply, how do we get crude oil?
We drill wells down into the earth and bring it up.
What is crude oil?
A mixture of substances, most of which are hydrocarbons.
What are hydrocarbons?
Molecules containing only atoms of Hydrogen and Carbon.
What method is used to separate compounds in crude oil?
Fractional Distillation
Explain how compounds in crude oil are separated:
1) The oil is heated until most of it is in gaseous form.
2) It is fed into the fractionating column.
3) The column has a temperature gradient, hottest at the bottom, and coolest at the top.
4) Substances rise until the temperature is lower than their boiling point. (Bitumen stays liquid and is collected out the bottom)
5) Causing them to condense and allows them to be collected.
In the fractionating tower, what stops separated liquids from running down the column and remixing?
Bubble Caps
What are Saturated Hydrocarbons?
Containing only single bonds between carbon atoms.
What are Unsaturated Hydrocarbons?
Containing double or triple bonds between carbons.
In crude oil separation, the compounds near the top are different to those near the bottom, what changes as you go up the column?
- Shorter Hydrocarbons have lower boiling points, and rise to the top, where it is cooler.
- Big compounds have high boiling points and stay low.
How many carbons would a compound of bitumen be likely to possess?
70+
How many carbons would a compound of refinery gases be likely to possess?
~3
What is a use for the following compounds:
- Bitumen
- Fuel Oil
- Diesel
- Kerosene
- Gasoline
- Refinery Gases
Bitumen - Surfacing roads
Fuel Oil - Fuel for large ships and power stations
Diesel - Fuel for some cars and larger vehicles
Kerosene - Aircraft fuel
Gasoline - Car fuel
Refinery Gases - Domestic heating and cooking
What is another name for Gasoline?
Petrol
The really long chain hydrocarbons are not needed in as high of a quantity as they are produced, what is used to make smaller, more useful molecules out of these larger ones?
Cracking
Which hydrocarbons are very viscous and which are thinner and paler?
Long hydrocarbons are viscous (higher b.p)
Short hydrocarbons are thinner and paler (lower b.p)
What is Octane?
A short-chain hydrocarbon used in petrol (gasoline). It is in very high demand.
What is thermal decomposition?
Breaking down molecules into simpler molecules through heating them.
True/False:
Cracking is a form of thermal decomposition?
True - The temp is very high
600-700*C
What is cracking?
The breakdown of larger alkanes into smaller more useful hydrocarbons.
What are the conditions required for Cracking to happen?
temp = 600 - 700 *C
powdered catalyst = Silica or Alumina
What is Silica?
Silicon Dioxide
SiO2
A powdered catalyst used in cracking.
What is Alumina?
Aluminium Oxide
Al2O3
A powdered catalyst used in cracking.
How is the process of cracking carried out?
A vaporised hydrocarbon is passed over a powdered catalyst. (at about 600-700*C, the catalyst is Silica or Alumina)
How does the cracking reaction occur?
The vaporised hydrocarbon breaks down when it comes into contact with the catalyst, producing a mixture of short-chain alkanes & alkenes.
When a fuel is burnt, it releases energy. In what form is this energy?
Heat (thermal)
Why are hydrocarbons great fuels?
The combustion reaction gives out lots of energy as the reactions are extremely exothermic.
hen you burn hydrocarbons in oxygen, complete combustion occurs.
Write a word equation for complete combustion:
Hydrocarbon + Oxygen -> Carbon Dioxide + Water
What are the products formed in complete combustion?
- Carbon Dioxide (CO2)
- Water (H20)
When does incomplete combustion occur?
When there is insufficient/no oxygen for complete combustion.
Name a household product that is likely to undergo incomplete combustion is neglected:
Boilers, that use carbon compounds as a fuel.
What are the products for incomplete combustion?
- Carbon Monoxide (CO)
- Carbon (soot) (C)
- Carbon Dioxide (CO2)
- Water (H20)
Why can Carbon Monoxide (CO) be dangerous to humans?
It binds irreversibly with the haemoglobin in red blood cells to reduce the oxygen carry capability of the blood.
True/False:
Alkanes are Hydrocarbons?
True - They are just chains of Carbon surrounded by Hydrogen.
What is the general formula of Alkanes?
C2 H2n+2
What are the names of the first 5 Alkanes?
Methane Ethane Propane Butane Pentane
Molecular and Structural formula of Methane?
Molecular: CH4
Structural: CH4
Molecular and Structural formula of Ethane?
Molecular: C2H6
Structural: CH3CH3
Molecular and Structural formula of Propane?
Molecular: C3H8
Structural: CH3CH2CH3
Molecular and Structural formula of Butane?
Molecular: C4H10
Structural: CH3CH2CH2CH3
Molecular and Structural formula of Pentane?
Molecular: C5H12
Structural: CH3CH2CH2CH2CH3
Why are all Alkanes known as Saturated Hydrocarbons?
They all contain only single bonds between the carbon atoms. (No Double Bonds)
What is formed when a Halogen reacts with an Alkane?
Haloalkanes
What Halogens react with alkanes?
Chlorine (Cl2)
Bromine (Br2)
What is needed for the Halogens to react with Alkanes?
Ultra-Violet Light
In a reaction for a Haloalkanes reaction, what type of reaction is it?
How does the reaction occur?
A substitution reaction.
A Hydrogen atom from the alkane is substituted with Chlorine or Bromine.
True/False:
Alkenes are a type of hydrocarbon?
True
Why are Alkenes known as unsaturated hydrocarbons?
They contain Carbon-Carbon Double Bonds (C=C), this means they can make more bonds as the double bond could open up allowing for more bonds.
What is the general formula for Alkenes?
Cn H2n
Molecular and Structural formula of Ethene?
Molecular = C2H4 Structural = CH2CH2
Explain why Methene does not exist:
There is only one carbon (meth-) and this means there is no double-bonds.
Molecular and Structural formula of Propene?
Molecular = C3H6 Structural = CH3CHCH2
Molecular formula of Butene (But-1-ene &But-2-ene)?
Molecular = C4H8
When Halogens mix with Alkenes, what is the product?
Haloalkanes
When a Halogen reacts with an Alkene, what type of reaction occurs? and why?
Addition, because the C=C double bond is split and a halogen atom is added to each carbon.
What experiment determines between Alkenes and Alkanes?
The test shows the presence of C=C double bonds.
- Shake the mixture with orange bromine water.
Colourless = Alkene, because the bromine molecules (orange) react with the alkane to form Dibromoalkane (Colourless)
Orange = Alkane, The alkane is already saturated and doesn’t react with the Bromine. Therefore, the solution stays orange.
What is the general formula of an Alcohol?
Cn H2n+1 OH
What is the functional group for Alcohols?
-OH
Molecular formula of Methanol?
Molecular = CH3OH
Molecular formula of Ethanol?
Molecular = C2H5OH
Molecular formula of Propanol?
Molecular = C3H7OH
Molecular formula of Butanol?
Molecular = C4H9OH
When an alcohol is oxidised, it forms Carboxylic acids.
What does oxidised mean?
The alcohol is oxidised as it gains oxygen.
True/False
Alkenes have double the number of Hydrogen as Carbon
True - CnH2n
What is the oxidising agent in the oxidation of Alcohol to form Carboxylic Acids?
Potassium dichromate (VI) in dilute sulphuric acid. (aka - Acidified Potassium Dichromate (VI))
Describe how Ethanol is turned into Ethanoic Acid
The ethanol is Heated with Acidified Potassium Dichromate (VI).
What is Microbial Oxidation?
Microorganisms break down alcohols as energy, producing carboxylic acids as a by-product.
How does Microbial Oxidation work?
Some microorganisms are able to use alcohols as an energy source. To do this, they use Oxygen in the air to oxidise alcohols.
Carboxylic acids are made as a by-product.
How is Ethene produced?
From Crude Oil, or Cracking.
What reacts with Ethene to create Ethanol?
Steam
The reaction between Ethene and Steam to create Ethanol is what type of reaction?
Addition, because water is added to the molecule.
What conditions are needed for the reaction between Ethene and Steam to produce Ethanol?
Temp = 300*C Pressure = 60-70 atmospheres
What catalyst is required for the reaction between Ethene and Steam to produce Ethanol?
Phosphoric acid (H₃PO₄)
Why is the Hydration of Ethene a good method for producing ethanol?
- Ethene is cheap
- Not much is wasted
Why is the Hydration of Ethene a bad method for producing ethanol?
- Crude oil is non-renewable and will start to run out.
- Meaning that Ethene will become very expensive
What method is used to create ethanol for beer and wine?
Fermentation of Ethene
What is the raw material used in the Fermentation method?
Sugar, e.g. Glucose - This is converted to ethanol using yeast.
What is the formula for fermentation of yeast?
C6H12O6 -> 2 C ₂H ₅OH + 2CO2
Why does yeast act as a catalyst in the fermentation method?
It contains Enzymes (natural catalysts) whih speed up the reaction.
What are the conditions required for Fermentation of glucose to occur?
Temp = 30*C, optimal temperature for yeast enzymes. Anaerobic = No oxygen.
Why is important that fermentation is done in anaerobic conditions?
Otherwise the Oxygen may turn the Ethanol into Ethanoic Acid (ingredient in vinegar).
Why is the Fermentation of Glucose a good method for producing ethanol?
- All raw materials are renewable resources.
- Sugar Cane and Yeast are widely available
Why is the Fermentation of Glucose a bad method for producing ethanol?
- Ethanol produced is low concentration, so it must be further distilled to increase strength.
- The product also needs to be purified.
What is the functional group of the Carboxylic Acids?
-COOH
What are the first four Carboxylic Acids?
Methanoic Acid
Ethanoic Acid
Propanoic Acid
Butanoic Acid