Condensed notes for Chemistry: 1,2, and 3

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Limestone: Heat + clay to make cement. Cement + sand = mortar. Mortar + aggregate = concrete.
Thermal Decomposition: CaCO3+ heat = CaO + CO2. All metals decompose to produce oxides and CO2.
Neutralising: CaO + H = CaHO +H
2O A solution of calcium hydroxide in water tests for CO
2. 2.
Carbonates: Carbonates react with acids to produce carbon dioxide, a salt and water.
Ore: Naturally occurring rocks that provide an economic starting point for the manufacture of metals.
Reduction: Metals less reactive than carbon are extracted from their oxides by reduction with
Electrolysis: Metals more reactive (carbon) are extracted by electrolysis of molten compounds.
Copper: Smelting then electrolysis. Copper-rich ores are rare and mining has environmental impacts.
Phytomining: Plants absorb metal compounds then plants are burned to produce compound-rich ash.
Bioleaching: Bacteria to produce leachate solutions that contain metal compounds.
Copper: obtained from solutions of copper salts by electrolysis or by displacement using scrap iron.
Extraction: Expensive because: there are many stages in the processes and a lot of energy is
Recycling Reasons: Uses limited resources. Extraction is expensive / energy / effects the environment.
Blast furnace iron: Contains 96% iron. The impurities make it brittle and so it is only used as cast iron.
Steels: Alloys, mixtures of iron with carbon. Alloys can be designed to have properties for specific
uses. Low-carbon steels = easily shaped. High-carbon steels = hard. Stainless Steels are resistant to
Transition Metals:Higher points and densities. Good Conductors. Ductile. Malleable
Copper: Good conductor, can be bent but is hard enough to make pipes or does not react with
Aluminium and Titanium: Low density and resistance to corrosion make these useful metals.
Crude oil: a mixture of a very large number of compounds.
Alkanes. Formula = CnH2n+2. Methane, Ethane, Propane And Butane. -- represents a covalent bond.
Fractional Distillation: The many hydrocarbons in crude oil may be separated into fractions, with
similar carbon atoms by evaporating the oil and allowing it to condense at different temperatures.
Hydrocarbons: Larger molecules = lower flammability, more viscous and higher melting points.
Combustion: Partial = CO, H particulates. Total = CO
20, 2, H SO
20, 2 and nitrogen oxides (need high
Problems: SO2/
Nitrogen Oxides = Acid Rain. CO2 = Global Warming. Solid Particles = Global
Sulphur: Removed from fuels before they are burned or sulphur dioxide is removed after

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Biofuels: Produced from plant material. Economic, ethical and environmental issues with their use.
Cracking: Hydrocarbons can be cracked to produce smaller, more useful molecules. This process
involves heating the hydrocarbons to vaporise them. The vapours are then passed over a hot catalyst.
Alkenes: Unsaturated hydrocarbons. Formula = C
nH2n .
Turn bromine water, from orange to
colourless. Polymers: many small molecules (monomers) join together to form very large molecules
(polymers.) Problems: Many polymers are not biodegradable, and this can lead to problems with
waste disposal.…read more

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Air: Mixture of gases with different B/M points so can be fractionally distilled to provide raw
Ionic Bonding: Complete transfer of outer shell electrons. Between metals and non-metals. Strong
electrostatic attraction between oppositely charged ions. Conduct when molten or dissolved as they
carry a current. Form giant lattice structures. High melting/boiling points.
Covalent Bonding: Sharing of electron pairs between ions. Simple Molecular = strong electrostatic
attraction, but weak intermolecular forces so low M/B points. No ions = No charge = No current.…read more

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Subject Content
a mass spectrometer can identify substances very
quickly and accurately and can detect very small
the mass spectrometer can also give the
HT only
relative molecular mass of each of the
The molecular mass is given by the molecular ion
substances separated in the column.
Knowledge of fragmentation patterns is not
C2.3.…read more

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Even though no atoms are gained or lost in a chemical reaction, it is not always possible to obtain the
calculated amount of a product because:
the reaction may not go to completion because it is reversible / some of the product may be lost
when it is separated from the reaction mixture/ some of the reactants may react in ways different
from the expected reaction.
Percentage Yield: The amount of a product obtained compared with the maximum theoretical.…read more

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Electrolysis: Pass an electric current through an ionic substance that is molten/in solution to break
them down into elements. The broken down substance is called the electrolyte. Used to electroplate
Reduction: At the cathode, positively charged ions gain electrons
Oxidation: At the anode, negatively charged ions lose electrons
If there is a mixture of ions, the products formed depend on the reactivity of the elements involved.
Aluminium: Manufactured by the electrolysis of a molten mixture of aluminium oxide and cryolite.…read more

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Cations: Add Sodium Hydroxide to excess. Calcium, Magnesium and Aluminium (dissolves in excess)
form white precipitates. Copper= Blue
Iron2+= Green
Iron3+= Brown
Carbonates: ABC + dilute acid Carbon Dioxide. Limewater will turn Cloudy.
Halide: Silver Nitrate Solution + Dilute Nitric Acid Silver Precipitate. Chloride Bromide=cream
Sulphates: Dilute Hydrochloric Acid + Barium Chloride Solution Barium Sulphate + ABC
Titration: Put 50cm3 of the alkali in a flask with phenolphthalein.…read more


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