1 Acid Metal Salt Hydrogen 2 example essay topic

CHEMISTRY STUDY NOTES: Module 1: The Chemical Earth 1.1 Construct word and balanced formulae equations of chemical reactions as they are encountered. STEPS: 1. General equation 2. Word equation 3. Formula equation 4. Balanced equation 5.

Ionic equationNeutralisation: 1. base + acid salt + water 2. calcium hydroxide (aq) + hydrochloric acid (aq) calcium chloride + water 3.4. 5.1. base + acid salt + water 2. ammonium hydroxide + hydrochloric acid ammonium chloride + water 3.4. 5. Displacement of Metal for Hydrogen: 1. acid + metal salt + hydrogen 2. Sodium + hydrochloric acid sodium chloride + hydrogen 3.4. 5.1. acid + metal carbonate salt + carbon dioxide + water 2. hydrochloric acid + copper carbonate copper chloride + carbon dioxide + water 3.4.

5. (If one salt is insoluble precipitation) 1. salt AB + salt CD salt CB + saltAD 2. Lead nitrate (aq) + potassium iodide (aq) Lead iodide (s) + potassium nitrate (aq) 3.4. 5.1. salt AB + salt CD salt CB + saltAD 2. barium nitrate (aq) + hydrogen sulphate (aq) barium sulphate (s) + hydrogen nitrate (aq) 3.4. 5. Displacement of one metal for another: 1. metal X + salt AB metal A + Salt XB (base) 2.3. 4.5. Corrosion: 1. metal + oxygen metal oxide (base) 2. magnesium + oxygen magnesium oxide 3.4. 5.1. non-metal + oxygen non-metal oxide (acid) 2. phosphorus (s) + oxygen (g) phosphorus oxide 3.4. 5.1. non-metal + oxygen non-metal oxide 2. calcium (s) + oxygen (g) calcium oxide 3.4. 5.1.

Non-metal oxide + water ACID 2.3. 4.5. 1. Decomposition: heat 1. Metal Carbonate Metal oxide + carbon dioxide 2.3. 4.5. 1.

Active Metal + water salt + hydrogen 2.3. 4.5. 1. fossil fuel + oxygen carbon dioxide + E + water 2. propane (g) + oxygen (g) carbon dioxide (g) + energy + water (l) 3.4. 5.1. 2 Identify the difference between elements, compounds and mixtures in terms of particle theory. "ALL MATTER IS MADE UP OF ATOMS " Homogeneous: A substance of uniform composition throughout, e.g. water, sugar, aluminium, petrol or whisky. Heterogeneous: A substance having non- uniform composition where we can recognise small pieces of the material which are different from other pieces, e.g. strawberry jam, wood, or water with ice in it. Impure substance (or mixture): A substance contaminated with small amounts of one or more other substances. Mixtures: o A substance which is made by mixing elements and / or compounds.

Though there are no chemical bonds between the mixed items (e.g. salt water). o Can be separated into 2 or more pure substances by physical / mechanical means. o Can be homogeneous / heterogeneous o Displays properties of the pure substances making it up Has properties that can change as the relative amounts of the substances present are change do Has variable composition (varied amounts of pure substances) o Sea water, air, coffee, mil, petrol, whisky, brass Pure Substance: o Cannot be separated into 2 or more pure substances by physical / mechanical means. o Is homogeneous o All properties throughout sample are constant, incl. colour, density, melting and boiling points. o Properties do not change Fixed composition o Table salt, sugar, copper, aluminium, diamond, gold, polyethylene and alcohol. Element: A pure substance which all the atoms are the same and that cannot be decomposed into simpler substances (e.g. copper, nitrogen, oxygen). Most formulae are written as the symbol except some are diatomic, (H 2, O 2, N 2) as well as the halogens (F 2, Cl 2, Br 2, I 2). Compound: A pure substance which can be decomposed into simpler substances, such as elements (e.g. Na Cl). The formula tells us how the substance exists and also tells us the number of atoms of each element in 1 unit / molecule of the substance. o Made up of two or more element so Always has elements present in the same ratio by mas so Has properties that are quite different from those of the elements that make it up. o Two or more non- metals bond to form MOLECULAR (covalent) compounds. o Metal + Non-metal bond to from IONIC compounds 1.3 Identify that the biosphere, lithosphere, hydrosphere and atmosphere and contain examples of mixtures of elements and compounds. Layers of the earth: Inner Core: Solid, made of mostly iron and nickel, 1300 km thick.

Outer Core: Molten, made of mostly iron and nickel, 3500 km thick. Mantle: Semi-solid, mainly iron and magnesium silicates, 6400 km thick. Crust: 15-35 km thick. Atmosphere: o 200 to 300 km thick, mostly mixture of elements of nitrogen, oxygen and argo no Contains small amounts of gaseous compounds of water, carbon dioxide, nitrogen dioxide, sulfur dioxide and carbon monoxide. Lithosphere: o Part of crust and solid top of mantle, contains: o Rocks (made up of silicates- compounds of silicon, oxygen and metals). o Sand (silicon dioxide, ground up shells and finely divided dirt). o Soil (mixture of - clays, compounds of aluminium, silicon, oxygen - sand, decomposing animal and vegetable matter. o Mineral ores (oxides, sulfides, carbonates, sulfates and chlorides of metals mixed with and silicates). o Coal, oil and natural gas, (mixtures of compounds of carbon formed from decaying plant and matter. o MOSTLY formed of compounds, includes rare elements such as gold, silver, platinum and carbon (as diamond). Biosphere: o Part of crust, including hydrosphere and atmosphere Includes living matter such as animals, plants, algae and bacteria (which are carbon-containing compounds with water and small amounts of minerals). o Include carbohydrates (sugars), proteins, fats and vitamins, many being insoluble (cellulose, skin, hair).

Some make up organism, some help organism function. o Free elements (apart from dissolved O 2 and N 2) are rare. Hydrosphere: o Watery part of crust mainly composed of water. o Rivers and lakes made up of water dissolved in oxygen, nitrogen, carbon dioxide, sodium, calcium, magnesium chlorides and sulfides. o There is 0.05% dissolved matter in fresh water, making it a solution (homogeneous). Though microscopic life present make it heterogeneous. o Ground water is a mixture with larger amounts of solids such as chlorides and sulfides. o Mixtures of hydrosphere are only compounds. 1.4 Identify and describe procedures that can be used to separate naturally occurring mixtures of: - Solids of different sizes Sieving: used to separate lumps of larger solids from powdery substances using a sieve Magnetic Separation: separates magnetic solids from non-magnetic solids. - Solids and liquids Filtration: Solution passes through filter paper while solid remains on top of paper. The liquid that passes through is the filtrate.

Decanting: The process of carefully pouring off the liquid and leaving the solid undisturbed at the bottom of the container. Dissolved solids in liquidsVaporising: to vaporize the solvent we boil the solution. Evaporation: the liquid is heated to a temperature below its boiling point so that some of the particles "escape" from the surface of the liquid into the air. Evaporating from dryness: the process of heating a solution in an evaporating basin to drive off all the solvent. Distillation: the process in which a solution or mixture of the liquids is boiled with the vapour formed being condensed back to a liquid in a different part of the apparatus and so separated from the mixture.

The mixture of the impure liquid is placed in a flask and left to boil. The liquid changes to vapour, rises up the neck of the flask and diffuses down the side arm and into the water-cooled condenser, where the vapour is cooled and condensed back into a liquid which is collected in a beaker. This collected liquid is the distillate. - Liquids- Gases MODULE 2: ELEMENTS 2.1 o Uncombined elements in the atmosphere include: 21% oxygen, 78% nitrogen, 1% argon. There are also small amounts of the other noble gases: helium, neon, krypton, xenon and radon, as these do not react with other elements. o Other elements that occur as uncombined elements are: sulfur and metals such as gold, sliver and platinum (and to a small extent copper). o The remaining 90 elements occur as compounds, as they are chemically reactive and form compounds with other elements. THE MORE REACTIVE AN ELEMENT IS, THE LESS CHANCE THERE IS OF FINDING IT IN THE EARTH AS AN UNCOMBINED ELEMENT. o Sodium, potassium, calcium, magnesium, fluorine and chlorine are very reactive and are never found as free elements. o Copper and sulfur have moderate reactivity and are sometimes found as elements but mostly as elements. o Gold, platinum and the noble gases often occur naturally as uncombined elements. o Most elements react to some degree and are found combined in nature as oxides, sulfides and carbonates.

Most metals are found in the ground e.g. Iron oxides. 2.2 Metals: o (usually) solids at room temperature (except mercury) o lustrous o good conductors of heat and electricity malleable (can be rolled into sheets) and ductile (able to be drawn into wires) o high density and high melting point so Elements that do not possess the above properties are non-metals, though elements that have properties of both classes are called semi-metals. 2.3 Physical properties and uses of elements: Physical properties of elements often determine their uses. The physical properties of metals often determine which product they will be used for, including melting point, density, electrical conductivity, hardness and tensile strength. Metal Use Property Aluminium Aircraft Low density Iron (or steel- 98% iron) Motor cars and trains High tensile strength Copper Electrical wiring (Although for high voltage transmissions aluminium is preferred) High electrical conductivity (same electrical conductivity with a lower density) Tungsten Filaments in electric light bulbs High melting point Non- Metal Use Property Carbon (as graphite) -Electrodes in common dry cells (batteries) - Lubricant -Electrical conductivity-slippery nature Carbon (as diamond) - jewellery - hardness & resistance to scratching, high refractive index Liquid Nitrogen - Cooling agent Freezing / melting /boiling points Argon - Fill electric light bulbs - Lack or inertness (reactivity) Helium -Fill Balloons - Less reactive than hydrogen (which has a lower density) Chemical properties are often considered to select non-metal uses.