Introduction To Organic Chem Flashcards
Organic Chemistry is all about what?
Carbon compounds
What does the general formula of organic compounds show you and give examples
An algebraic formula that can describe any member of a family of compounds. E.g alcohols = CnH2n+1OH
What does the empirical formula of organic compounds show you and give examples
The simplest ratio of atoms of each element in a compound. E.g ethane C2H6 = CH3
What does the molecular formula of organic compounds show you and give examples
The actual number of atoms of each element in a molecule e.g C4H10 (butane)
What does the structural formula of organic compounds show you and give examples
Show the atoms carbon by carbon with the attached hydrogens and functional groups. E.g CH3CH2CH2CH2OH
What does the skeletal formula of organic compounds show you and give examples
Shows the bonds of the carbon skeleton only with functional groups. Hydrogen and carbon atoms are not shown which makes it easier to draw cyclic hydrocarbons
What does displayed formula of organic compounds show you and give examples
Shows how all the atoms are arranged and all the bonds between them, see physical flash cards for examples
What is a homologous series?
A sequence of compounds with the same functional group and similar chemical properties
What is the general formula for alkanes
CnH2n+2
Name 8 homologous series and their suffixes/ prefixes
• Alkanes-ane
• Alkenes- ene
• Carboxylic acids- oic acid
• Branched alkanes- alkyl
• Halogenoalkanes- fluoro/chloro/Bromo/iodo
•alcohols- ol
• aldehydes- al
• Ketones- one
Give the steps for naming organic compounds
• Count the longest consecutive carbon chain and deduce the prefix
• Look for the functional group and decide the suffix
• Number the functional group (if required)
• look for additional groups e.g CH3: methyl, ethyl,propyl
• Number the additional things
• Put the name together
• Di, tri, tetra
How has IUPAC naming contributed to organic compounds
Scientific ideas can be communicated across the globe more effectively.
Give the functional group for alkanes, alkanes, Haloalkenes, alcohols, aldehydes, ketones, Carboxylic acids
• C-H
• C=C
• C-X x, is any halogen
• CHO
• C(O)
• COOH
How many bonds does a carbon atom have in alkane so that means they are what?
4 single bonds so they are saturated
Draw the structure of cyclohexane
Check physical flash cards to see if you got it right
What is another word for petroleum
Crude oil
What type of hydrocarbons are found in petroleum
Alkanes
What is the process of separating crude oil?
Fractional distillation
Describe in 4 steps how fractional distillation works
• Crude oil is vaporized at 350*C
• Vaporized crude oil goes into the fractionating column and rises up the trays. Larger hydrocarbons don’t vaporize due to high boiling points so the run to the bottom of the column to form a gooey residue.
• As vapour rises up the column it gets cooler. Because alkanes have different chain lengths which lead to different boiling points so each faction condenses at different columns
• Hydrocarbons with the lowest hydrocarbons don’t condense, they’re drawn off as gases at the top
What is cracking?
Cracking is breaking long-chain alkanes into smaller hydrocarbons. It involves breaking c-c bonds
Why are less popular heavier fractions cracked?
Because they are not high in demand and therefore less valuable
What are the two types of cracking
Thermal and catalytic
Describe thermal cracking
- High temperature and pressure
- Produces lots of alkenes and few alkanes
- Alkenes are used to make polymer e.g plastics and polyethene made from ethene
>1000C at 70 atm
Describe catalytic cracking
- Uses a zeolite catalyst at a slight pressure and high temperature, 450C
- Produces aromatic hydrocarbons and motor fuels
*Using a catalyst lowers costs cause it speeds up the rate of reaction saving time since it can be done at low pressure and temperature
What does burning alkanes lead to?
Pollutants
What products are formed during complete combustion
Carbon dioxide and water, a blue flame
What causes incomplete combustion
Less oxygen to react, orange and smoky flame due to pure carbon burning red hot
Why and how is carbon monoxide harmful as a result of incomplete combustion
• It is poisonous
• Binds to the same site on haemoglobin molecules as oxygen molecules so oxygen can’t be carried around the body
• It can be removed by catalytic converters in cars
Why is carbon harmful as a product of incomplete combustion
• Causes breathing problems
• Can also build up in engines
Describe how burning fossil fuels contributes to global warming
• Produces green house gases
• Green house gases absorb infrared energy (heat). They emit some energy back towards the earth, making the earth warmer
• This is known as global warming
How is oxides of nitrogen (NO) produced?
When high pressure and temperature cause nitrogen and is then atoms from the air to react together
Describe how ground level ozone is formed and how this affects people
• Hydrocarbons and nitrogen oxides react in the presence of sunlight
• This is a component of smug
• Form ground level ozone which affects peoples eyes
• Aggravates respiratory problems and causes lung damage
• Catalytic converters remove unburnt hydrocarbons and oxides of nitrogen from exhaust
How is acid rain formed and what are its effects
• When burnt fossil fuels contain sulfur
• Sulfur reacts to form sulfur dioxide gas
• In the atmosphere, it dissolves in the moisture and is converted to sulfuric acid which causes acid rain
• Acid rain destroys trees and vegetation, corroding buildings and statues and kills fish in lakes
How can sulfur dioxide be removed
Powdered calcium carbonate or calcium oxide is mixed with water to make an alkaline slurry. When flue gas mix with alkaline slurry, acidic sulfur oxide reacts with calcium compounds to form harmless salt, calcium sulphite
Give examples of catalytic converters
Platinum and rhodium
What are the problems of incomplete combustion of long chain alkanes and why
Longer chain alkanes require more oxygen to combust completely
Draw the displayed formula from of 3-fluoro-2,2-dimethylpentane
Check physical flashcards for answers
Define fractional distillation, thermal cracking and addition polymerisation
• Fractional distillation: separated into mixtures of compounds with similar boiling points/similar sized molecules
• Thermal Cracking: To make alkenes/propene/shorter molecules
• Addition polymerisation: molecules joined together or to produce a long chain molecule
Plantinum, palladium and rhodium are metals used inside catalytic converters. A very thin layer of metals is used on a honeycomb ceramic support.
Explain why a thin layer is used in this way
To provide a large surface area to give the catalyst a large surface area to volume ratio
How to name molecules
• Always draw the molecule out
• Always count the longest carbon chain
What is the use of nitrogen monoxide in catalytic converters
convert toxic gas such as carbon monoxide to carbon dioxide and nitrogen monoxide turns to nitrogen gas
Safety signs on the fuselage of the helicopter state that the air inlets to the engine need to be cleaned out regularly.
Suggest how this partial blockage might affect the performance of the helicopter engine.
Less energy given out by the fuel / engine is less powerful / less efficient / needs to burn more fuel to get the same energy / increased costs due to need to use more fuel
