11 - Organic Chemistry Flashcards
What is the Homologous series and the general characteristics it has? [3]
- a family of similar compounds with similar chemical properties
- same general formula
- displaying a trend in physical properties
What are alkanes? [2]
saturated hydrocarbons whose molecules contain only single covalent bonds
What are properties of alkanes? [3]
- boiling point increases with chain length
- shorter chains evaporate more easily
- shorter alkanes are more flammable - easier to burn
What is the general formula for an alkane? [1]
CₙH₂ₙ₊₂
What is the general formula for an alkene? [1]
CₙH₂ₙ
What are the prefixes for the words? [10]
- meth
- eth
- prop
- but
- pent
- hex
- hept
- oct
- non
- dec
What is the family name for an alkane? [1]
‘ane’
What is the family name for an alkene? [1]
‘ene’
Why are alkenes unsaturated? [1]
because they contain a carbon double bond
What are alkenes? [2]
unsaturated hydrocarbons whose molecules contain one double covalent bond
How are alkenes produced? [1]
cracking
What is the general formula for an alcohol? [1]
CₙH₂ₙ₊₁OH
What is the family name for an alcohol? [1]
‘ol’
What is the bonding like in an alcohol? [1]
C - OH
What is the bonding like in an alkene? [1]
C = C
What is the bonding like in an alkane? [1]
H
H - C - H
H
(single covalent bonds)
How can ethanol be formed? [2]
- fermentation
- reaction between ethene and steam
What is formed when an alkene is reacted with water? [1]
alcohol
What is formed when an alkene reacts with hydrogen gas? [1]
alkane
What is formed when an alkene is reacted with bromine? [1]
dibromoalkane
What is made when ethene reacts with hydrogen gas? [1]
ethane
What is made when ethene reacts with water? [1]
ethanol
What is the test for an unsaturated compound? [1]
- mix compound with bromine water
What is a positive result for testing for an unsaturated compound? [2]
- alkene: it decolourises the bromine water (from brown - colourless)
- alkane: no reaction and colour stays the same
What is a saturated compound? [1]
it only has single bonds
What is a hydrocarbon? [2]
an organic compound which only contains hydrogen and carbon
What is the formula for complete combustion? [2]
hydrocarbon + oxygen –> carbon dioxide + water
What type of reaction is combustion and why? [2]
- exothermic
- it releases loads of energy in the process
What is complete combustion? [1]
excess oxygen forms CO₂ + H₂O
What is incomplete combustion? [1]
limited oxygen forms CO + H₂O
What is crude oil and where do we get it from? [3]
- fossil fuel
- we get it from deep under the ground
- mixture of lots of different compounds
Most of crude oil’s compounds are what? [1]
hydrocarbons
What does fractional distillation do? [3]
- separates all the different hydrocarbons from crude oil
- separates them into useful fractions
- heats up the crude oil
What are the stages of the fractional distillation compounds from cool to hot? [5]
- refinery gas
- gasoline fraction
- naptha
- diesel oil
- bitumen
What is refinery gas used for? [1]
bottled gas for heating and cooking
What is gasoline fraction used for? [1]
for petrol in cars
What is naptha used for? [1]
feedstock for making chemicals
What is diesel oil used for? [1]
fueld in diesel engines
What is bitumen used for? [1]
road surfaces
What is the other name for crude oil? [1]
petroleum
What is the main constituent of natural gas? [1]
methane
What are the uses of ethanol? [2]
- as a solvent
- as a fuel
What type of reaction is cracking and what does it mean? [2]
- thermal decomposition reaction
- breaking down molecules by heating them
What is the formula for cracking? [1]
long chain alkane –> shorter alkane + alkene
What are properties of alkenes? [2]
- more reactive than alkanes
- they can be added together to make polymers
Why can alkenes be added to make polymers? [1]
their double bond can break to form two or more bonds
What are properties of alcohols? [3]
- flammable
- soluble
- can be oxidised to form carboxylic acids
What is the functional group of a carboxylic acid? [1]
-COOH
What happens when cracking happens? [2]
- larger alkane molecules are cracked
- smaller alkanes and alkenes are produced
What conditions are needed for cracking to happen? [2]
- suitable catalysts needed
- high temperature needed
What are some fossil fuels that produce carbon dioxide on combustion? [3]
- coal
- natural gas
- petroleum
What are polymers? [2]
large molecules built up from many smaller molecules called monomers
What is the bond like for an amide? [1]
O = C - N - H
What is the bond like for an ester? [1]
O - C = O
What does acid + alcohol make? [1]
ester
What does acid + amine make? [1]
amide
What is a synthentic polymer? [1]
made in the lab (artificially made)
If there’s only one product, what type of reaction is it? [1]
addition
What is produced from a condensation reaction? [2]
- water
- product
What is the difference between an addition reaction and a condensation reaction? [4]
- addition reactions are formed from 1 monomer which has a double bond
- condensation reactions are formed from 2 different monomers
- addition reactions form no byproducts
- condensation reactions form water as a byproduct
How do the properties of the fractions obtained from fractional distillation change from bottom to top? [2]
- decreasing chain length
- lower boiling points
What is one of the main polymers in plastic? [1]
polypropene
What has happened to form poly(ethene)? [2]
- addition polymerisation
- using ethene monomers
