Unit 22, 23 & 24 - Hydrocarbons/ Alcohols And Carboxylic Acids/ Polymers Flashcards
What are hydrocarbons
Compounds that only contains carbon and hydrogen atoms
What is the general formula for alkanes
CnH2n+2
What an homologous series?
A series of molecules that have a general formula
What does it mean if molecules are saturated
If all Carbon-Carbon covalent bonds are single bonds
What type of hydrocarbon is saturated
Alkanes
What is the order of prefixes
Meth, eth, prop, but
What is the general formula for alkenes
CnH2n
What is a functional group
An atom or group of atoms this is mainly responsible for a molecules chemical properties
What is the functional group for alkanes
C-H
What is the functional group for alkenes
C=C
How do you show an isomer on a diagram
Moving the double bond
What is complete combustion
When hydrocarbons are burned and produce CO2 and H2O as there is enough oxygen
All atoms are fully oxidised
What is incomplete combustion
When hydrocarbons are burned without enough oxygen so soot and carbon monoxide are produced
What is the test for alkanes and alkenes
Adding bromine water
What are the results for the bromine water test
Alkenes become colourless but alkanes don’t
Why do alkenes react with bromine water
The double bond reacts with bromine so it loses its colour
What is the product when ethene reacts with bromine
1,2-dibromoethane
What is an addition reaction
When reactants combine to form one larger product molecule without other products
What is the formula for ethanol
C2H5OH
What is ethanol in alcoholic drinks made from
Sugars
What is broken down for the sugars needed for ethanol
Starch molecules
What turns starch into sugars for ethanol
Enzymes
Where is the starch for ethanol found
In seeds
What is fermentation
When enzymes in the yeast turn sugars into ethanol and carbon dioxide
What is the word equation for fermentation
Glucose –>ethanol + carbon dioxide
What type of respiration is yeast fermentation
Anaerobic
What concentration of alcohol does fermentation produce up to
15%
How are more concentrated solution of ethanol formed
By fractional distillation
Why does fractional distillation work to produce a higher concentration of ethanol
Ethanol has a lower boiling point than water
What is the general formula for alcohols
C2H2n+1OH
Give 2 properties of alcohols
Can be oxidised to form carboxylate acids
Produce CO2 and H2O in complete combustion
What is the functional group for alcohols
OH
What does an alcohols reactivity depend on
The length of the carbon chain, shorter means more reactive
Besides drinks, what else are alcohols used for (2)
Cosmetics
Medical drugs
What 3 alcohols are widely used for fuels
Methanol, ethanol
Explain the core practical - The combustion on alcohols
Measure mass of am alcohol burner and cap
Put 100cm3 of water in a conical flask
Measure temp of water and clamp above alcohol burner
Light the wick of the primer and allow water to heat up by 40C
Put cap on, measure temp and measure mass of burner
Calculate mass of alcohol burned to produce a 1C rise in temp
Repeat using different alcohols
What happens to wine if it is left open to the air
It turns to vinegar
What causes the sharp taste of vinegar
Ethanoic acid
What happens to ethanol to make it ethanoic acid
Oxidation, an oxygen molecule collides and one atom takes 2 hydrogen atoms to make H2O, the C atom without the hydrogen atoms forms a double bond with the other oxygen atom
What is the functional group for carboxylic acids
COOH
What are oxidising agents
Compounds containing oxygen used to oxides molecules in a reaction
Give 3 properties of carboxylic acids
Form solution with pH less than 7
React with bases to form salt and water
React with carbonates to form salt, water and CO2
What is used to test form carbonate rocks like chalk and limestone
Vinegar, it fizzes and produces CO2
What are plastics made from
Polymers
What are polymers made from
Monomers
What is polymerisation
The process where monomers join together
What happens in addition polymerisation
The C=C bond breaks and form sing,e bonds on the ends
What does a repeating unit show
How the monomers has changed and how it repeats throughout the chain
What is a synthetic polymer
A polymer made in a lab
Give 3 naturally occurring polymers
DNA, starch and proteins
What is the full name for PVC
Poly(chloroethene)
What is poly(ethene) used for
Plastic bags and bottles
What is poly(propene) used for
Buckets
What is PVC used for
Window frames, gutters
What is PTFE used for
Non-stick coatings for frying pans
How are polyesters made
By condensation polymerisation
What happens in condensation polymerisation
Monomers join together and eliminate a small molecule such as water
What is the functional group for esters
-COO-
Describe the functional group for esters
C-O with =O on top of C
When are esters formed
When carboxylic acids react with alcohols
Why is the formation of esters a condensation reaction
Water is also produced
What is the word equation for the production of esters
Carboxylic acid + alcohol -> Ester + water
Where is the water molecule taken from for the production of esters
O-H from carboxylic acid, H from alcohol
What must each monomer have in order to create a polyester
2 functional groups, one at each end
What are polyesters used for
Bottles and clothes
What are most monomers used for synthetic polymers obtained from
Crude oil
What does biodegradable mean
They break down naturally by the environment
What does incinerated mean
Burned
What is a negative of burning plastics
They release carbon dioxide and some toxic substances
What helps to reduce the amount of waste in incinerators
Reusing materials like plastic bags
What are the main 6 steps for recycling polymers
Collect waste Sort waste Dispose waste that can’t be recycled Clean polymers and grind into clippings Purify clippings Melt clippings and process into a new product
What are used to help make sorting the polymers easier
Symbols and codes
