C1 - Carbon Chemistry Flashcards
Name four additives and what they do.
- Food colouring (more appetising)
- Flavour enhancers (brings out taste and smell)
- Antioxidants (preserve food)
- Emulsifiers (help oil and water blend together)
What is a emulsifier molecule made us of?
Hydrophilic end (likes water and hates oil)
Hydrophobic tail (likes oil hates water)
What happens when eggs and meat are cooked?
PROTEINS are in these.
By heating it the chemical bonds break (DENATURES).
This makes a edible texture.
What happens when potatoes are heated?
They have a rigid cell wall, which can be digested.
When heated cell walls are heated the walls rupture.
Starch swells up and speeds out making it easier to digest.
What is the the word and symbol equation when baking powder is heated?
Sodium hydrogencarbonate > sodium carbonate + carbon dioxide + water
2NaHCO(3) > Na(2)CO(3) + CO(2) + H(2)O
How to test for carbon dioxide?
Use limewater and if it turns cloudy CO(2) is present.
How do you make an ester?
Acid + Alcohol > Ester + Water
What properties do perfumes need?
- Easily evaporate (so you are able to smell it)
- Non toxic (it will not poison you)
- Non irritant (will not burn you)
- Insoluble in water (will not wash off easily)
What is the method of making Esters?
1) Mix 10cm(3) of carboxylic acid(ethanoic) with 10cm(3) of alcohol(ethanol).
2) Add 1cm(3) of concentrated sulfuric acid and warm.
3) Put the mixture in 150cm(3) of sodium carbonate solution.
Describe the force between the particles in a solid.
There are strong forces which holds them in a lattice arrangement.
Describe the force between the particles in a liquid.
There are some forces meaning they are free to move and don’t keep a definite shape.
Describe the force between the particles in a gas.
Gases don’t have any forces meaning they don’t keep there shape at all.
Describe volatility.
There are weak attractions so at low temperatures the particles can evaporate easily.
What is a solution?
This is a mixture of a solute and a solvent, which do not spread out.
What is a solute?
This is the substance being dissolved.
What is a solvent?
The liquid which the solute is dissolving in.
What is soluble?
This means it will dissolve.
What is insoluble?
This means it will not dissolve.
What is the solubility?
The measure of how much will dissolve.
Why is nail varnish insoluble in water?
There is a stronger attraction between the nail varnish than the water molecules.
Why is nail varnish soluble in nail varnish remover?
There is stronger attractions between the remover than the nail varnish.
What are pigments used for?
They give paints their colours.
What are colloids (paints)?
A colloid consists of tiny particles which are dispersed in something else (not dissolved).
Describe how water based paints work.
When the water evaporates this leaves behind the coloured pigment.
Describe how oil based paints work.
When the oil is oxidised by oxygen it turns solid.
What is the special pigment which changes colour when heated?
Thermochromic
What is the special pigment which glows in the dark?
Phosphorescent
What are polymers?
They are long chain molecules made from many monomers
Explain what addition polymerisation is.
Unsaturated hydrocarbons are put under pressure and a catalyst to make a long chain saturated of hydrocarbons.
Explain alkanes
- single bonds (saturated)
- all have an ‘a’ (methane)
What is the formula of alkanes?
C(n)H(2n+2)
Explain alkenes.
- double bonds (unsaturated)
- All have an ‘e’ (ethene)
What is the formula for alkenes?
C(n)H(2n)
What do alkenes react with.
They can react with bromine water and it will turn this colourless
Label the fractions from top to bottom
1) LPG (liquid petroleum gas)
2) Petrol
3) Naphtha
4) Kerosene
5) Diesel
6) Oil
7) Bitumen
What kind of hydrocarbons filter off at the top and bottom of the fraction
Long chin molecules exit at the bottom because they have higher BP so they turn into a liquid quicker
If they have short chains then they will exit where its cooler as they have a lower BP and will turn into less quids at lower temperatures
What does cracking do?
This splits up long chain hydrocarbons
What is formed when a long chain hydrocarbons is cracked?
Short chain alkane and an alkene
What conditions are needed for cracking?
- Powdered catalyst (aluminium oxide)
- 400 to 700 degrees
What does cracking do to help?
This helps match the supply and demand
What is the equation of complete combustion?
Hydrocarbon + oxygen > carbon dioxide + water
What is the equation is incomplete combustion?
Hydrocarbon + oxygen > carbon dioxide + water + carbon monoxide + carbon
What is the evaluation of the atmosphere?
1) volcanoes give out steam and carbon dioxide
2) green plants evolved to produce oxygen
3) ozone layer allows evolution of complex animals
What is the percentage of atmospheric gases?
78% nitrogen
0.035% carbon dioxide
21% oxygen
Summarise the carbon cycle
- respiration, combustion and decay of plants and animals add carbon dioxide and remove oxygen
- photosynthesis removes carbon dioxide and oxygen
- these all balance out the gases in the atmosphere
How is acid rain cause?
When fossil fuels are burnt sulphur dioxide is in the air. When this mixes with clouds it turns into sulphuric acid then falls as acid rain
What is the word and symbol equation for a catalytic converter?
Carbon monoxide + nitrogen oxide > nitrogen + carbon dioxide
2CO + 2NO > N(2) + 2CO(2)
What should you consider when buying fuels?
T oxicity
E ase of use
A vailability
C ost
U sefulness
P ollution
S torage
