GCSE Chemistry Revision
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Transcript of GCSE Chemistry Revision
ChemistryRandom Notes to RememberProbably not everything by a long way
Contents
Contents
Contents
General EquationAcids and Bases in Fertilisers
Contents
General Equation
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Acids and Bases in FertilisersFertiliser Name Acid and Base in the Fertiliser
Ammonium Nitrate(NH₄NO₃)
Acid = nitrogen (aka nitric acid)Base = ammonia
Ammonium Sulphate(NH₄2SO₄)
Acid = sulphur (aka sulphuric acid)Base = ammonia
Ammonium Phosphate(NH₄3PO₄)
Acid = phosphorus (aka phosphoric acid)Base = ammonia
Potassium Nitrate(KNO₃)
Acid = nitrogen (aka nitric acid)Base = ammonia
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The Haber ProcessManufacture of Ammonia
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The Haber Process
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Manufacture of Ammonia1. Nitrogen2. Hydrogen3. Mixer4. Compressor5. Iron catalyst chamber
▫ 450°C▫ 200 atmospheres
6. Chiller▫ Ammonia (but not other
gases) liquefies▫ -40°C – -50°C
7. Recycle▫ 72% recycled▫ Hydrogen and nitrogen
8. Final article▫ Ammonia out 28%
12
3
4
56
7
8
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Extraction of Drugs from PlantsThe Process of Extraction from Plant MaterialBatch or Continuous
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Extraction of Drug
•Plants are crushed in the first stage to break through call walls
•This should release the needed chemical•An organic solvent is used rather than
water because the chemicals are not soluble in water
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The Process of Extraction from Plant Material
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Continuous or BatchContinuous Batch
• Ammonia is made as part of a continuous process
• Most drugs are also made as part of a continuous process
• This is normally after having it on batch while it is being tested and approved
• Beer and alcohol are made in batch
• Some drugs are also pat of the batch process because there may be a problem with the drug
• This will then be put on continuous supply once approved
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The IngredientsPolar BondsDry Cleaning
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Ingredients...1. Enzymes 2. Optical Brighteners
• It helps to remove food stains by breaking down fat and proteins
• The fatty acids, glycerol, and amino acids are removed in the water
• They work best at 40°C as it is warm but not hot so they don’t denature
• This is economical and environmentally friendly too
• A chemical that increases the apparent whiteness of a fabric to make it appear whiter than it really is
• It does this by reflecting ultra-violet light in the blue region of the spectrum
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...More Ingredients...3. Bleach 4. Water Softener
• An ingredient to break down the natural colour constituents of a stain
• The most common is sodium perborate (‘oxygen bleach’)
• It is a powder made from borax and hydrogen peroxide and used in detergents like tetrahyrate (NaBO₃4H₂O)
• It creates an alkaline solution in water (hydrogen peroxide) which has a bleaching effect
• A chemical (like sodium chloride) that treats the water by replacing calcium and magnesium ions and salts (aka ‘hardness’)
• It then replacing them with sodium ions to make the water more efficient
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...And The Final Ingredient
5. Detergent
The Detergent Molecule
• Similar to emulsifiers• Synthetic cleaning or
wetting agent that is a mixture of compounds to remove dirt and oil
Hydrophilic head
Hydrophobic tail
Has a charge
Has no charge
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Polar Bonds
• A water molecule has a slight charge, aka polar,
• Therefore they can only dissolve charged compounds, aka ionic compounds
Attracts electrons very strongly
Electrons
δ+ δ+δ-
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Dry Cleaning
•Dry cleaning uses a solvent rather than water making it ‘organic.’
•This means it has no charge so breaks down compounds with no charge
•You would dry clean because:▫Water doesn’t remove all stains▫Water destroys some fabrics
E.g. Wool
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ChromatographySulphate IonsHalide Ions
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Chromatography
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Test for Sulphate Ions•Used in purifying water•Barium Chloride (BaCl₂) is an ionic compound
used to find sulphate•Barium Chloride + Magnesium Sulphate +
Magnesium Chloride• If sulphate is present a white precipitate will form
(insoluble in water)
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Test for Halide Ions • Used in purifying water• Silver Nitrate (AgNO₃) is used to find halide ions• Add AgNO₃ to your water sample and if a precipitate forms, halide ions
are present
Halide Ion Colour of Precipitate
Chloride (Cl⁻) White (AgCl)
Bromide (Br⁻) Cream (AgBr)
Iodide (I⁻) Yellow (AgI)
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The Carbon AtomAllotropeDiamondGraphiteBuckminster FullereneNanotubes
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The Carbon Atom
• Atomic number 6• Non-metal• Can conduct electricity• Singly covalently bonded
C
xx
xx
x x
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Allotrope
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Diamond
•Each C atom is joined to 4 other C atoms by covalent bonds in a tetrahedral structure
•The strength of the bonds make diamond very hard and strong
The Tetrahedral Structure
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Graphite
•Each C atom has only 3 covalent bonds formed which makes it weaker than diamond
•Graphite exists as sheets of carbon with the spare electron from each atom free to move between the sheets
•Thus, there is a sea of electrons creating an electric current
C
CC C
x
xo
xo
x oSpare electron
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Buckminster Fullerene
•Normally C-60 Fullerene•Used to make nanotubes•It is in a spherical shape originally
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Nanotubes• Hexagonally arranged
carbon atoms to make tiny (microscopic) and very strong tubes
• These are made from a series of fullerenes, as if stretched into tubes
• Uses:1. Improve catalysts2. Reinforcement in
tennis rackets3. Semi-conductors in
electrical circuits