SC22-24 Organic Chemistry Flashcards
Define hydrocarbon
- Contains hydrogen and carbon
- **only **
Define homologous series
‘Family’ of organic compounds that have the same functional group and similar chemical properties
Define functional group
Atom or group of atoms that are responsible for the characteristics and reactions of an organic compounds
What are alkanes?
A homologous series with the general formula of CnH2n+2
Name the first four alkanes
- methane
- ethane
- propane
- butane
Alkanes contain saturated bonds. What does the term saturated mean?
They only contain single bonds between the carbons
What is the molecular formula for methane?
CH4
What is the molecular formula for ethane?
C2H6
What is the molecular formula for propane?
C3H8
What is the molecular formula for butane?
C4H10
What are alkenes?
Homologous series that contain an unsaturated bond and have a chemical formula of CNH2N
What does the term unsaturated bond mean?
Containing a double carbon bond
How can alkenes make more bonds?
By opening up the double C bond
What are addition reactions?
Reactions wherein one molecule combines with another, forming a larger molecule and no other products
Ethene and Bromine are in an addition reaction. What is the product formed?
1,2 diobromoethane
Why are alkenes more reactive than alkanes?
Their double bond allows them to merge with other molecules, whereas alkanes don’t have a double bond which limits their reactivity
Define isomer
Chemicals that have the same molecular formula but different arrangements of atoms
Give an example of an alkene that has isomers
Butene:
- but-1-ene
- but-2-ene
Where is the double bond placed in but-1-ene?
On the first carbon bond
Where is the double bond placed on but-2-ene?
On the second carbon
When considering isomers, what side of the chain do we begin counting from?
Take the shortest route: this could be going from right to left or from left to right
How can we test for a difference between alkanes and alkenes?
- shaking bromine water with the two solutions
- alkenes will decolourise the solution, changing it from orange yellow to colourless
- alkanes will result in no change, which means the solution remain orange-yellow
Which of the two homologous groups undergo complete combustion?
Alkanes and Alkenes
Which of the two homologous groups undergo incomplete combustion?
Alkenes
What are the products formed from complete combustion?
Carbon dioxide and water
What is the general formula of alcohols?
CnH2n+1OH
What is the functional group of alcohols?
hydroxyl group (OH)
State the chemical properties of alcohols
- produce C02 and H20 in a complete combustion reaction
- can be oxidised to form carboxylic acids
- react with reactive materials, forming H20 as one of the products
What are the uses of alcohol?
- cosmetics
- medical drugs
- varnishes
- methanol and ethanol used as fuels
Name the first four alcohols
- methanol
- ethanol
- propanol
- butanol
What is the molecular formula for ethene?
C2H4
What is the molecular formula for propene?
C3H6
What is the molecular formula for butene?
C4H8
What is the molecular formula for pentene?
C5H10
What is the main alcohol found in alcoholic drinks?
Ethanol