violet s chemistry notes!

PURE CHEMISTRYUPPER SECONDARY CHEMISTRY 2021PURE SCIENCE NOTby violet, 2021 TABLE OF CONTENTS: Chapter 1: Kinetic Particle Theory and the 3 States of Matter 4 Kinetic Particle Theory 4 Changes in State 4 Diffusion 5 Factors affecting the rate of diffusion 5 Chapters 2-3: Experimental Techniques, Separation and Purification 5 Separation Methods 5 Testing for Purity 6 Chapter 4: Elements, Compounds and Mixtures 7 Elements 7 Compounds 7 Mixtures 7 Chapter 5: Atomic Structure 7 Subatomic Particles 7 Relative Charge and Mass 7 Isotopes 7 Representation of Atomic Structure 7 Chapters 6-7: Chemical Bonding: Ionic, Covalent and Metallic 8 Ionic compounds 8 Simple covalent compounds 8 Metallic bonding 8 Properties of metals 8 Macromolecules 9 Chapters 8-10: Formulae, Stoichiometry and the Mole Concept 10 Stoichiometry Formulae 10 Ionic equations 10 1

Chapters 11-12: Acids, Bases and Salts [including QA] 10 Types of Oxides 10 Properties of Acids and Alkalis 11 Methods of salt preparation 11 Basicity, Strength and Concentration 11 Solubility rules 11 Sub-chapter: Qualitative Analysis 12 Test for anions 12 Test for cations 12 Chapter 13: Redox Reactions 13 What is a redox reaction? 13 Rules for Assigning Oxidation Numbers / States 13 Oxidation 13 Reduction 13 Chapter 14: Metals 14 Alloys 14 Reactions of metals 14 Reactions of metal compounds 15 Extraction of iron 15 Steel 16 Prevention of Rusting 16 Recycling of metals 16 Chapter 15: Electrolysis 17 What is electrolysis? 17 Molten vs. Aqueous electrolytes 17 Applications of electrolysis 17 Factors affecting preferential discharge of ions in aqueous electrolytes 17 Simple/Electrochemical Cell 18 Chapter 16: The Periodic Table 18 Group I. Alkali Metals 18 Group VII. Halogens 19 Group 0. Noble Gases 19 Transition Elements 19 Chapter 17: Energy from Chemicals 20 Energy changes in reactions 20 Types of Fuels 21 Chapter 18: Rate of Reaction 22 Chemical reactions 22 Factors affecting rate of reaction 22 Catalysts 22 2//violet’s chem nes

Chapter 19: Ammonia 23 Properties of Ammonia 23 Laboratory Preparation of Ammonia 23 Haber Process 23 Calcium Hydroxide 23 Chapter 20: Air and Atmosphere 24 Composition of Air 24 Air is a mixture of several gases. 24 Pollutants 24 Air pollution is the condition in which air contains a high concentration of chemicals that may harm living things or damage non-living things. 24 The Ozone Layer 25 Preventive methods 25 The Carbon Cycle 25 Global Warming 26 3//violet’s chem nes

Chapter 1: Kinetic Particle Theory and the 3 States of Matter Kinetic Particle Theory All matter is made of small particles that are continually moving and hence possess kinetic energy. Anything that has mass and takes up space is considered matter. Gases Liquids Solids No fixed shape or volume: particles can move freely at high speeds No fixed shape: particles can slide and roll over each other in translation Fixed shape and volume: particles can vibrate in fixed positions Wide spaces in between particles: can be compressed Very little space in between particles: cannot be compressed Particles far apart / widely spaced in a disorderly arrangement: low densities Particles closely packed in a disorderly arrangement: high densities Particles closely packed in an orderly arrangement: high densities Particles are held together by weak forces of attraction Particles are held together by strong forces of attraction Changes in State Melting and Boiling [Describe the original state of the particles.] When the substance is heated, the particles will move faster as they gain more kinetic energy. When particles gain sufficient kinetic energy to overcome the forces of attraction, they will separate and move apart into [liquid / gaseous state]. [Describe the new state of the particles.] Condensing and Freezing [Describe the original state of the particles.] When the substance is heated, the particles will move slower as they lose kinetic energy. When particles lose enough kinetic energy, they are no longer able to overcome the forces of attraction, so there are strong forces of attraction between them. They will get closer in [solid / liquid state]. [Describe the new state of the particles.] Volatile liquids are ones with boiling points close to room temperature. They evaporate easily. 4//violet’s chem nes

Diffusion Diffusion is defined as the random movement of particles of a substance. These particles have energy and unrestricted movement . They can move in any direction , though this occurs mainly in liquid and gaseous states. The net movement of the particles is from a region of higher to lower concentration . Eventually, particles are evenly distributed . Factors affecting the rate of diffusion Molecular mass Temperature States of Matter Heavier molecules travel slower than lighter molecules. The higher the temperature, the higher the amount of kinetic energy, the faster the molecule. Gas particles possess the most kinetic energy and are able to move freely and randomly. Liquid particles possess kinetic energy and are able to slide and roll over each other in translation. Solid particles possess the least kinetic energy and are unable to move freely. Chapters 2-3: Experimental Techniques, Separation and Purification Separation Methods NAME AND TYPE KEY STEPS AND USES Filtration: solid-liquid Filter the mixture using a filter funnel and filter paper. Used for filtration in water purification Crystallisation / Evaporation to Dryness: solute from solution Heat the solution until saturated. Check for saturation by dipping a cool glass rod into the solution. For crystallisation, let the solution cool and crystallise. Filter to get crystals, wash with distilled water and dry between filter paper. For evaporation to dryness, heat the solution until dryness. Used to separate salt from seawater. Simple Distillation: two miscible liquids with different boiling points that are far apart Heat the mixture and add boiling stones for smooth boiling. Condense the vapour in a condenser with cold water entering from the bottom. This ensures the water jacket is filled. The thermometer reads the temperature of the hot vapour passing into the condenser. Used for desalination and production of fermented liquor. 5//violet’s chem nes

Fractional Distillation: two miscible liquids with different boiling points that are close together Same steps as simple distillation. The additional fractionating column provides surface area for higher boiling point gases to cool and condense into liquid, while the gases that are boiling / of lower boiling point do not. The vapour at top is only the gas with lowest bp and is pure. Used for refining of crude oil. Used in the production of liquified oxygen and liquified nitrogen from liquified air. Separating Funnel: mixtures of immiscible liquids Remove the bottom layer(s) of liquid. Used to separate oil / chloroform and water. Sublimation: solid mixture of a substance that sublimes and others that are stable to heat Heat with an inverted funnel above the evaporating dish. The vapour of the substance that sublimes will resolidify on the inner walls of the filter funnel. Used mostly for purification of iodine, ammonium chloride or naphthalene. Paper Chromatography: determination of the identity and purity of complex mixtures Draw a starting line in pencil so there is no ink to separate. Let the solvent run as far as possible for better separation. The spots marked on the starting line should be above the solvent level, to prevent them from dissolving. Cover the boiling tube / beaker to prevent evaporation of the volatile organic solvent. Apply a locating agent to the paper. The identity of substance can be found using rf value. Used to separate pigments in flowers. Used to test for chemicals in food. Used to test athletes’ urine samples. rf value = distance moved by substance distance moved by solvent (affected by the type of solvent and temperature) Testing for Purity Impurities cause melting / boiling over a range Impurities typically decreas