1. 22/04/2017
Carbon Chemistry
OCR Gateway
W Richards

2. Fundamental concepts

3. Sodium chloride (salt)
Compounds
Sodium chloride (salt)
Methane
Compounds are formed when two or more elements are chemically combined. Some examples:
Glucose

4. Some simple compounds…
Methane, CH4
Carbon dioxide, CO2
Water, H2O
Key
Hydrogen
Oxygen
Carbon
Sulphur
Sulphuric acid, H2SO4
Ethyne, C2H2

5. More simple compounds…
Water
SO2
Carbon dioxide
H2O
Carbon monoxide
NaHCO3
Sodium hydrogencarbonate
Na2CO3
Sulfur dioxide
CO2
Sodium carbonate CO

6. Chemical formulae
The chemical formulae of a molecule or compound is simply a way of showing the ratio of atoms in it. For example… Na Cl
= sodium chloride (NaCl) K I
= potassium iodide (KI) O O
= potassium nitrate (KNO3) K N O

7. Chemical formulae Try drawing these: Water H2O Carbon dioxide CO2
Calcium sulphate CaSO4
Magnesium hydroxide Mg(OH)2

8. Simple chemical reactionsMg O H Cl
Magnesium oxide +
Hydrochloric acid
Magnesium chloride +
Water
MgO +
2HCl
MgCl2 +
H2O Mg O Cu S
Magnesium +
Copper sulphate
Copper +
Magnesium sulphate Mg +
CuSO4 Cu +
MgSO4

9. Rule 1– If two identical elements combine then the name doesn’t change
Naming compounds
Rule 1– If two identical elements combine then the name doesn’t change
This happens with the following elements: H2 N2 O2 F2
Cl2
Br2
These elements always go around in pairs (diatomic molecules). For example, hydrogen looks like this:

10. Naming compounds
Rule 2 – When two elements join and one is a halogen, oxygen or sulphur the name ends with ____ide
e.g. Magnesium + oxygen magnesium oxide
Sodium + chlorine
Magnesium + fluorine
Lithium + iodine
Chlorine + copper
Oxygen + iron
KBr
LiCl
CaO
MgS KF

11. e.g. Sodium + hydrogen + oxygen Sodium hydroxide
Naming compounds
Rule 3 – When three or more elements combine and two of them are hydrogen and oxygen the name ends with hydroxide
e.g. Sodium + hydrogen + oxygen Sodium hydroxide
Potassium + hydrogen + oxygen
Lithium + hydrogen + oxygen
Calcium + hydrogen + oxygen
Mg(OH)2

12. e.g. Copper + sulphur + oxygen Copper sulphate
Naming compounds
Rule 4 – When three or more elements combine and one of them is oxygen the ending is _____ate
e.g. Copper + sulphur + oxygen Copper sulphate
Calcium + carbon + oxygen
Potassium + carbon + oxygen
Calcium + sulphur + oxygen
Magnesium + chlorine + oxygen
Calcium + oxygen + nitrogen
AgNO3
H2SO4
K2CO3

13. Sodium + water sodium hydroxide + hydrogen
Balancing equations
22/04/2017
Consider the following reaction:
Sodium + water sodium hydroxide + hydrogen Na O H O H Na + H +
This equation doesn’t balance – there are 2 hydrogen atoms on the left hand side (the “reactants” and 3 on the right hand side (the “products”)

14. Balancing equations We need to balance the equation:
22/04/2017
We need to balance the equation:
Sodium + water sodium hydroxide + hydrogen Na O H O H Na O H Na O H + H + Na
Now the equation is balanced, and we can write it as:
2Na(s) + 2H2O(l) NaOH(aq) + H2(g)

15. Some examples 2 2 3 2 3 Mg + O2 Zn + HCl Fe + Cl2 NaOH + HCl CH4 + O2
22/04/2017 2
Mg O2
Zn HCl
Fe Cl2
NaOH HCl
CH O2
Ca H2O
NaOH H2SO4
CH3OH O2
MgO
ZnCl H2
FeCl3
NaCl H2O
CO H2O
Ca(OH) H2
Na2SO H2O 2

16. The structure of the atom
22/04/2017
The Ancient Greeks used to believe that everything was made up of very small particles. I did some experiments in 1808 that proved this and called these particles ATOMS:
Dalton
ELECTRON – negative, mass nearly nothing
PROTON – positive, same mass as neutron (“1”)
NEUTRON – neutral, same mass as proton (“1”)

17. Mass and atomic number 4 He 2
22/04/2017
Particle
Relative Mass
Relative Charge
Proton 1 +1
Neutron
Electron
Very small -1
MASS NUMBER = number of protons + number of neutrons He 2 4
SYMBOL
PROTON NUMBER = number of protons (obviously)

18. How many protons, neutrons and electrons?
Mass and atomic number
22/04/2017
How many protons, neutrons and electrons? 1 11 16 H B O 1 5 8 23 35
238 Na Cl U 11 17 92

19. Atoms, ions and molecules
An “atom” is simply one particle on its own in its “normal” state, e.g. a helium atom: Na +
An “ion” is an atom that has lost or gained electrons, e.g. sodium:
A “molecule” is a combination of atoms in a compound:

20. Examples of ionic moleculesCl -
Magnesium chloride: Cl Mg 2+ Mg + Cl - Cl
MgCl2
Calcium oxide: O Ca + 2+ 2-
CaO

21. Bonding introduced
22/04/2017 Cl
Hi. My name’s Johnny Chlorine. I’m in Group 7, so I have 7 electrons in my outer shell Cl
I’d quite like to have a full outer shell. To do this I need to GAIN an electron. Who can help me?

22. Bonding Cl Here comes one of my friends, Harry Hydrogen
22/04/2017 Cl
Here comes one of my friends, Harry Hydrogen
Hey Johnny. I’ve only got one electron but it’s really close to my nucleus so I don’t want to lose it. Fancy sharing? H Cl H
Now we’re both really stable. We’ve formed a covalent bond.

23. Here comes another friend, Sophie Sodium
Bonding
22/04/2017 Cl
Here comes another friend, Sophie Sodium Na
Hey Johnny. I’m in Group 1 so I have one electron in my outer shell. Unlike Harry, this electron is far away from the nucleus so I’m quite happy to get rid of it. Do you want it?
Okay - + Cl Na
Now we’ve both got full outer shells and we’ve both gained a charge. We’re both called IONS and we’ve formed an IONIC bond.

24. C1a – Making Crude Oil useful

25. Fuels
A “fuel” is something that can be burned to release heat and light energy. The main examples are:
Coal, oil and gas are called “fossil fuels”. In other words, they were made from fossils.

26. Hydrocarbons and crude oil
22/04/2017
Crude oil is a mixture of HYDROCARBONS (compounds made up of carbon and hydrogen). Some examples:
Increasing length
Longer chains mean…
Less ability to flow
Less flammable
Less volatile
Higher boiling point C H
Ethane
Butane C H

27. Distillation revision
22/04/2017
This apparatus can be used to separate water and ethanol because they have different _____ ______. The ______ will evaporate first, turn back into a _______ in the condenser and collect in the _______. The water remains in the round flask, as long as the _______ does not exceed water’s boiling point. This method can be used to separate crude oil.
Words – temperature, boiling points, ethanol, beaker, liquid

28. Forces between molecules
Weak force of interaction here
Longer molecules = stronger force of attraction

29. Fractional distillation
22/04/2017
Crude oil can be separated by fractional distillation. The oil is evaporated and the hydrocarbon chains of different lengths condense at different temperatures due to the different intermolecular forces between each molecule:
Fractions with low boiling points condense at the top
Fractions with high boiling points condense at the bottom

30. 22/04/2017
Crude Oil

31. Using Crude Oil Benefits Drawbacks
22/04/2017
Benefits
Drawbacks
Getting oil from unstable countries?
Cheap to extract
Burning fossil fuels causes pollution
Crude Oil
Wide range of uses as fuel
Used to make plastics
It takes millions of years to form
It’s going to run out

32. Cracking
22/04/2017
Shorter chain hydrocarbons are in greater demand because they burn easier. They can be made from long chain hydrocarbons by “cracking”:
Butane
Ethane
For example, this bond can be “cracked” to give these:
Ethene

33. Cracking Gaseous hydrocarbon Long chain hydrocarbon Heated catalyst
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Gaseous hydrocarbon
Long chain hydrocarbon
Heated catalyst
Liquid hydrocarbon
This is a THERMAL DECOMPOSITION reaction, with clay used as a catalyst
Cracking is used to produce plastics such as polymers and polyethanes. The waste products from this reaction include carbon dioxide, sulfur dioxide and water vapour. There are three main environmental problems here:
Carbon dioxide causes the _________ effect
Sulfur dioxide causes _____ _____
Plastics are not _____________

34. C1b – Using Carbon Fuels

35. Choosing a fuel Does it create pollution?
How much energy does it release?
Which fuel should
you use?
Is it toxic?
How much does it cost?
Is it easy to use, store and transport?

36. Burning Fuels – “Combustion”H O O H C O
Lots of oxygen:
Methane
Oxygen +
Carbon dioxide
Water +
What would a balanced symbol equation for this reaction look like?

37. Incomplete Combustion
Incomplete combustion is when a fuel is burned without having a plentiful supply of oxygen, e.g. when the Bunsen’s air hole is closed:
Water + O H
Methane C H
Oxygen + O C O
Some oxygen:
Carbon monoxide O H
Water + C H
Methane
Little oxygen: O
Oxygen + C
Carbon
Balanced symbol equations?

38. Incomplete Combustion
As well as producing carbon monoxide, incomplete combustion can also produce soot:
Little oxygen: C H
Methane O
Oxygen +
Water
Carbon
“Soot”

39. C1c – Clean Air

40. The Earth’s Atmosphere
22/04/2017
For the last 200 million years the atmosphere has remained roughly the same – it contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO2
Carbon dioxide, water vapour
Oxygen
Nitrogen
Noble gases

41. The Carbon Cycle CO2 in air
22/04/2017
2. Plants and algae release CO2 through respiration
CO2 in air
5. Burning fossil fuels also releases CO2
1. CO2 is taken in by plants and algae for photosynthesis and turned into carbohydrates, fats and proteins
4. Animals release CO2 through respiration
3. The carbon taken in by plants is then eaten by animals and the animals that eat them

42. Evolution of the Earth’s Atmosphere
22/04/2017
Carbon
dioxide
Methane
Ammonia
Oxygen
Nitrogen
Others
Present day atmosphere contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO2
4 Billion years
3 Billion years
2 Billion years
1 Billion years
Present day

43. Evolution of the Earth’s Atmosphere
22/04/2017
Volcanic activity releases CO2, methane, ammonia and water vapour into the atmosphere. The water vapour condenses to form oceans.
Some of the oxygen is converted into ozone. The ozone layer blocks out harmful ultra-violet rays which allows for the development of new life.
4 Billion years
3 Billion years
2 Billion years
1 Billion years
Present day
Green plants evolve which take in CO2 and give out oxygen. Carbon from CO2 becomes locked up in sedimentary rocks as carbonates and fossil fuels. Methane and ammonia react with the oxygen and nitrogen is released.

44. Population and Pollution
The human population is growing exponentially, particularly in countries like China and India:
Population
Time
This has a number of effects on the environment:
Resources –
more resources needed, e.g. deforestation
Farming –
less land available for crops
Bigger population means…
Pollution –
More phosphates, nitrates, CO2 and SO2
Waste –
more waste needs to be disposed of

45. Pollution What causes pollution?
Sulfur dioxide causes acid rain that kills aquatic life and damages buildings and metals. It’s caused when fuels containing sulfur are burned.
Carbon monoxide is a poisonous gas formed by incomplete combustion.
Oxides of nitrogen can cause photochemical smog and acid rain, and are formed in internal combustion engines

46. Reducing Pollution from vehicles
A number of suggestions:
1) Buy a new, smaller, cleaner car
2) Buy a “hybrid” car
3) Convert your car to run on biodiesel
4) Make sure your car has a catalytic converter:
Carbon monoxide + oxygen carbon dioxide
2CO + 2NO N2 + 2CO2
5) Use the train or a bus!

47. C1d – Making Polymers

48. Hydrocarbons revision
22/04/2017
Crude oil is a mixture of HYDROCARBONS (compounds made up of carbon and hydrogen). Some examples:
Increasing length
Longer chains mean…
Less ability to flow
Less flammable
Less volatile
Higher boiling point C H
Ethane
Butane C H

49. Alkanes Alkanes are SATURATED HYDROCARBONS. What does this mean?
22/04/2017
Alkanes are SATURATED HYDROCARBONS. What does this mean?
HYDROCARBONS are molecules that are made up of hydrogen and carbon atoms
SATURATED means that all of these atoms are held together by single COVALENT bonds, for example: C H
Ethane
Butane C H
Alkanes are fairly unreactive (but they do burn well). The general formula for an alkane is CnH2n+2

50. General Formulae for Alkanes
22/04/2017
Instead of circles, let’s use letters…
Methane (n=1) H C
Ethane (n=2) H C
Propane (n=3) H C
Butane (n=4) H C
General formula for alkanes = CnH2n+2

51. Alkenes ALKANES ALKENES
22/04/2017
Alkenes are different to alkanes; they contain DOUBLE COVALENT bonds (a bond that has two shared electrons). For example:
Ethane
Ethene
ALKANES
ALKENES
Butane
Butene
This double bond means that alkenes have the potential to join with other molecules – this make them REACTIVE. Alkenes turn bromine water colourless.

52. Bromine goes colourless
Testing for alkenes
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Bromine water
This is an “addition” reaction where the colour change is caused by the formation of a colourless dibromo compound.
Oil
Bromine goes colourless

53. General Formulae for Alkenes
22/04/2017
Ethene (n=2) H C
Propene (n=3) H C
Butene (n=4) H C
General formula for alkenes = CnH2n

54. Monomers and Polymers
22/04/2017 C H
Ethene
Here’s ethene again. Ethene is called a MONOMER because it is just one small molecule. We can use ethene to make plastics…
Step 1: Break the double bond
(this often requires high pressure and a catalyst)
Step 2: Add the molecules together:
This molecule is called POLYETHENE, and the process that made it is called POLYMERISATION

55. Another way of drawing it…
22/04/2017
Instead of circles, let’s use letters…
Ethene C H H C
Poly(e)thene
General formula for addition polymerisation: C n C n
e.g. C n H
CH3 C n H
CH3

56. Polyvinylchloride (PVC)
Some examples
22/04/2017 C n H Cl
CH3 C n H
Ethene –
polyethene C n H Cl
Vinylchloride –
Polyvinylchloride (PVC) C n H
CH3
Propene –
Polypropene

57. C1e – Designer Polymers

58. Uses of addition polymers
22/04/2017
Poly(ethene)
Poly(propene)
What properties would these polymers have?
Poly(styrene)
Poly(chloroethene), PVC

59. Words – high, low, strong, weak, stretched, rigid, slide
Structure of Plastics
1) Some plastics have ____ intermolecular forces between each molecule – these have __ melting points and can be ______ easily as the molecules _____ over each other.
2) Some plastics have _____ forces between each molecule. These have ____ melting points and are ____.
Words – high, low, strong, weak, stretched, rigid, slide

60. Outdoor Clothing
I love doing outdoor sports. I’d like to wear clothing that is tough but also lets my sweat out. What should I wear?

61. Nylon and Gore-Tex Nylon – lightweight, tough, waterproof, blocks UV
Gore-tex – nylon coated with PTFE – this means that it can allow perspiration to escape but rain cannot get in (it can “breathe”)

62. Gore-Tex
Gore-tex is a material made from nylon laminated with the polymer PTFE and its invention has been of great use in the world of outdoor sports. Here’s how it works:
Basically, the holes in the material are too small for water drops to pass through but big enough for sweat vapour. On its own, the membrane is too fragile so it is combined with nylon.
Outer fabric
Gore-tex
Inner fabric
Sweat

63. Words – recycling, greenhouse, decompose, biodegradable, poisonous
Disposal of plastics
1) Landfill sites - most plastics do not _________ which means that landfill sites are quickly filled up. Research is being carried out on __________ plastics.
2) Burning – this releases carbon dioxide which causes the ________ effect, as well as other ________ gases.
3) _______ – the best option, but difficult because of the different types of plastic
Words – recycling, greenhouse, decompose, biodegradable, poisonous

64. Biodegradable carrier bags
22/04/2017
This carrier bag has been made with flax fibre from industrial waste.

65. C1f – Cooking and Food Additives

66. The Chemistry of Cooking
The process of cooking food causes some chemicals to turn into others (i.e. a chemical change) and these are irreversible. For example, consider a protein molecule:
“Denatured”

67. The Chemistry of Cooking
Now consider a potato cell:
Cooking a potato causes the cell wall to break, leading to a softer texture. Starch grains also swell up and spread out.

68. Artificial Additives Why do we use additives? Some examples: Additive
Interesting information
Flavour enhancers
Can include traditional ingredients like salt, vinegar etc. Monosodium glutamate is often used in Chinese foods (its found in soy sauce)
Colour enhancers
Processing food often results in colour loss so colour enhancers are used. Could be natural like carotenes or artificial like tartrazine
Preservatives
Can include vinegar and sugar. Artificial preservatives are used to stop microbes growing and antioxidants stop fats going off
Vitamins and minerals
Can be used to replace those lost during cooking

69. E numbers
If artificial additives are “approved” they are given an E number:
E100–E199 (colours)
E200–E299 (preservatives)
E300–E399 (antioxidants, acidity regulators)
E400–E499 (thickeners, stabilizers, emulsifiers)
E500–E599 (acidity regulators, anti-caking agents)
E600–E699 (flavour enhancers)
E900–E999 (miscellaneous)
E1000–E1999 (additional chemicals)

70. Emulsions What’s an emulsion?
22/04/2017
What’s an emulsion?
It’s a mixture of oil and water, like in salad dressing…
Butterfat
Paint is an emulsion. Other examples:
Watery liquid
Milk
Cream
Butter

71. Different thicknesses of cream
Why use emulsions?
22/04/2017
Emulsions can have varying textures and this makes them useful. Some examples:
Different thicknesses of cream
Paint and mayonnaise

72. Emulsifiers
22/04/2017
An emulsifier is an additive that will stop oil and water from seperating, like in mayonnaise.
How they work:
I’m an emulsifier – I’ll sort this out with my hydrophobic end and my hydrophilic end!
I don’t want to mix with you!
Water
Oil
The water and oil drops become “coated” and insulated from one another, which prevents them from seperating.

73. Uses of emulsifiers in food
22/04/2017
Emulsifiers are used:
In bread, to stop large _____ developing when it bakes
In low fat spreads, to allow the oil and water to be _____
In ice cream and spray cream, to ______ the foam
In sponge cakes, to make tiny pockets of ____
In chocolate, to stop melted chocolate forming _______
Words – crystals, air, holes, mixed, stabilise

74. Sodium hydrogen carbonate sodium carbonate + water + carbon dioxide
Baking Powder
Baking powder is used to make bread rise:
Sodium hydrogen carbonate sodium carbonate + water + carbon dioxide
NaHCO3(s) Na2CO3(s) H20(g) + CO2(g) 2
Gas
Testing for carbon dioxide:
Limewater
Limewater turns milky/cloudy

75. C1g – Smells

76. Ethanol + ethanoic acid ethyl ethanoate + water
Perfumes
Perfumes are synthetically made from chemicals called “esters”. Here are some facts about perfumes. Why are these things important?
Perfumes are non-toxic
They are non-irritants
They evaporate easily
They do not dissolve in water
They don’t react with water
A typical perfume reaction:
Ethanol ethanoic acid ethyl ethanoate water
C2H5OH CH3COOH C2H5OOCCH H2O

77. Words – soluble, solute, solvent, solution, insoluble
Solutions revision
If a substance CAN be dissolved it is called __________
If a substance CANNOT be dissolved it is called _________
Words – soluble, solute, solvent, solution, insoluble

78. Solubility words Solute
Something that CAN dissolve is described as being…
How much of something that can be dissolved is called…
Something that CANNOT be dissolved is described as being…
A solution that CAN’T dissolve anything else is…
The solid that will be dissolved is the…
The mixture of solute and solvent is called the…
The liquid that the solute will be dissolved into is the…
Solute
Solution
Solvent
Soluble
Insoluble
Saturated
Solubility

79. Making a solution A solution forms because there are:
Weak forces of attraction between solute molecules
Strong forces of attraction between solute and solvent molecule
For example, nail varnish remover works because the nail varnish remover molecules are attracted to the nail varnish molecules with a stronger attraction than water molecules are. Esters can be used as solvents.

80. Cosmetics I think that the testing of cosmetics should be allowed.
No way! I totally disagree.
The testing of cosmetics on animals is currently banned in the EU. Who do you agree with and why?

81. C1h – Paints and Pigments

82. “Ingredients” in paint
Paint is an example of a “colloid” – a mixture of one or more substances in a liquid but which are not dissolved. The molecules have a large surface area:volume ratio and, as such, they have a large surface tension and are difficult to separate.
“Ingredients” in paint
Function
Solvent
Gives the paint its colour
Pigment
Sticks the pigment to the surface
Binding medium
Thins the paint, making it easier to spread

83. Water based vs Oil based
“Water-based paints”
“Oil-based paints”
In water-based paints the paint dries when the _______ evaporates, causing them to dry in around one ______. In oil-based paints the solvent has to ________ and then the oil is _______ by oxygen in the air, which takes longer and paint brushes have to be cleaned with ____ ___ rather than water.
Words – white spirit, evaporate, water, hour, oxidised

84. Thermochromic Paint
Thermochromic paint is paint that changes colour when heated. Some uses:
Acrylic paints can be added to thermochromic paint to give it an even wider range of colours.
Here’s a strange use of this paint:

85. Phosphorescent Paint
Phosphorescent paint is paint that contains pigments that can glow in the dark. They do this by “storing” energy and then release it over time:
The original “glow-in-the-dark” paint contained radioactive materials so this paint is much safer!