IGCSE Chemistry Topical Notes PDF

r/IGCSE Resources Topical Notes by Chapter for Cambridge IGCSE Chemistry (0620) Authored by Veda 1st edition, for examination until 2025 © r/IGCSE...

r/IGCSE Resources Topical Notes by Chapter for Cambridge IGCSE Chemistry (0620) Authored by Veda 1st edition, for examination until 2025 © r/IGCSE Resources 2024 Chapter 1 : States of Matter - I ice water solids liquids & gazes pour , i & water solids · kinetic theory. veda. ritha... · ~-C E- ↑ · -- when substance is heated , particles absorb thermal - · energy which is & · Fixed volume Fixed shape high density. , , ~ converted to kinetic energy. · doms vibrates in place Heating solid causes particles to vibrate more , 3 as temperature increases they vibrate to the point solid's structure breaks 3 It melts closely packed together regular pattern ·. with more heating the liquid expands as well until particles at , Liquids:... A ::... - surface gain enough energy to escape 3 the liquid boils when by reach..... - - these changes are shown on a heating curve & reverse is a cooling in temperature effects curve , these curves show how changes · Fixed 3 take shape of container volume changes of state. Less dense than solids more dense than gas · Pressure 8 temperature in , Particles move and slide past each other. · Gases :: gases I the more the temperature increases , the volume of gas also · not fixed volume take shape of container , increases. and the density decreases if volume increases. Lowest density a lot of space betwee particles · , if you have gas stored in containera Squeezed , the pressure so gases are easily compressed. increases as you decrease volume. · Random particles 3 Particles more quickly. Particles Collide with each other 3 the · Gases 8 Kinetic theory. sides of the container (this is how Pressure Gaseous particles are in constant random motion. is created). creates inside a closed container is pressure that gas produced by gas hitting the walls of container state changes.. An increase in kinetic energy increases if temperature increases. With increase in kinetic energy particles Melting. Evaporation. , · solid > - Liquid temperature. more faster and collide with walls more frequently. heat kinectic liquid -> gas at any energy > increase in pressure. - Decrease in volume · = energy and melting only occurs at evaporation happens at the surface only specific melting energy particles escape surface at temp known as point. · high any temperature. Boiling. · larger the surface area the the , more Liquid to gas quickly a liquid evaporates · · heat needed to form. bubbles of gas below the surface of liquid allowing , condensation. liquid to escape from surface · occurs at boiling point (b P).. gas - liquid at range of temperatures. Freezing. when a gas is cooled , particles lose energy each · Liquid > - Solid 3 When they bump into o they they don't of melting occurs at , enough energy to bounce away instead reverse have · , same temperature requires lot of temp decrease they group together and form a liquid. extra notes diffusion T : diffusion is the movement of particles from area of high concentration to an area of low concentration and eventually concentration of particles will be even as they spread out to occupy all the space. diffusion happens on its own 3 doesn't require energy but it happens faster at higher temperatures Diffusion occurs faster in gases compared to liquids. at same temperature, gases dont diffuse at same rate. this is due to difference in molecular masses , lighter particles travel faster therefore they diffuse faster ,. this can be demonstrated in the reaction between ammonia (NH3) and hydrogen Chloride gas (HCI) inside glass tube. where the two meet , white smoke of ammonium gasses Chloride (NH (e) is formed. + However , they don't meet in the middle of the tube instead they Meet closer to the end where hydrogen Chloride (Mr = 36 5). is this is because ammonia , (Mr 17)'s molecules = are lighter so they travel faster than HCl. · This chapter was written while travelling , excuse the handwriting XD. Chapter 2 : Atoms Elements and , compounds cons conic Dot 3 Cross diagrams bonds. of the outer-shell electrons in ionic or covalent diagrams that show the arrangement - & compound or element. formed by group of loss or · ion is an electrically charged atom or atoms eg Nab : Cl-non-metal of electrons- stabilize. gain -this is done by atom to metal of electrons is done to gain full outer shell of electrons the loss/gain - XX of electrons - which is a more stable arrangement · · t XX X metals can lose electrons sodium atom sodium ion Metal : all and become positively charged Na ·*** ⑧ XO t ions known as cations ⑧ ** ** Non-metal non-metals : can gain Nation Ox from other atoms to Ce-ion electrons XX become negatively charged ions Lattice structure of ionic compounds. anions on compounhavagantlatticstructuredrepeatingfashionternating 00 known as. - there is more protons there is space than electrons now that for 7 electrons so it electron sodium lost an. is easier to lose the therefore it is positively 3 negative cons. Positive instead of existing electron. charged gaining 7. Properties of ionic compounds. - usually solid at rep points because of strong electrostatic high melting ? Boiling - > - When metals react with non-metals , ionic compounds are made to break bonds forces , a lot of energy will be needed.. metals lose their outer electrons which the non-metals atom. gain of electricity in molten or in solution - conductors. ions are held -good a charged b freely forces of positive 3 negative together by strong electrostatic this isbecausethepartie oringred - state because they are attraction between opposite charges. positions within the lattice attraction is known as ionic bond. - the force of. simple molecules giant covalent and covalent bonds veda structures ritha. · ~-( g Ef · covalent compounds are formed when pairs of electrons are shared between atoms. Diamond Graphite. allotropes of carbon with giant covalent structures , due +o Only non-metal elements participate in covalent bonding. · · difference in bond arrangement they are physically different when two or more atoms bond covalently , described they are as · in diamonds , carbon atoms bond with 4 other carbons forming molecules. a tetrahedron. * Dot' Cross diagrams can be used to snow covalent bonds eg : all bonds are identical , strong 3 have no intermolecular forces · H2 H20 NH3-ammonia carbon atoms bond to 3 other forming layers ⑳ ⑧⑧ in graphite , free electron per carbon to become hexagons of , leaving one * · O X N X H H H · H delocalized. but the layers ⑧ X the covalent bonds within layers are very strong weak intermolecular forces · attract to each other with H - H H H H 0 PROPERTIES OF : Graphite - - Single · has free delocalized electrons bond - So it can conduct electricity. N2 H N H diamond NEW - - · Layersare connectedby y it free electrons Triple bond - insulator - no slide C 0 CO2 over each other so graphite is 0 = high mp3bD-strong = - bonds smooth a Slippery. ↳ double bond hard dense high melting 3 boiling point - - - less dense than XX diamond. used in jewellery i N - - used in pencils 3 lubricants cutting tos1s used to make inert electrodes -. Silicon (IV) Oxide. properties of simple molecular compounds. b compound occurs sand ↳ macromolecular which naturally as quartz · small compound molecules are covalently bonded. they have low melting boiling - each oxygen atom covalent bonds with 2 silicon atoms 3 each or gases at room temperature. points so they are usually liquids Silicon atom bonds with 4 Oxygen atoms melting 3 boiling. · As molecule size increases, so does point. - tetrahedron is formed small molecules are poor electricity conductors.. · · there is weak intermolecular forces so they have low melting boiling point. comparing 3 Silicon diamond · intermolecular forces are weak so most small molecules are liquid/gas water high melting point , insoluble in · side is hard 3 has a · as molecule increases in size the intermolecular forces also increase doesn't conduct electricity &. this causes melting boiling point to increases. as it's naturally available used in making Siz is cheap compounds there's no free ions to · * Most molecular are poor conductors as of furnaces. most covalent compounds insulators in solid state line the insides Carry charge so are. sandpaper and to  The steeper the curve, the faster the rate of the reaction The curve is steepest initially so the rate is quickest at the beginning of the reaction As the reaction progresses, the concentration of the reactants decreases and the rate decreases shown by the curve becoming less steep When one of the reactants is used up, the reaction stops, the rate becomes zero and the curve levels off to a horizontal line The amount of product formed in a reaction is determined by the limiting reactant: ◦If the amount of limiting reactant increases, the amount of product formed increases ◦If the amount of the reactant in excess increases, the amount of product remains the same Drawing a tangent to the slope allows you to show the gradient at any point on the curve The steeper the slope, the quicker the rate of reaction  r/IGCSE Resources r/IGCSE Resources repository | r/IGCSE subreddit | Our Discord server igcse.reddit.com discord.gg/igcse Acknowledgments and Information: © UCLES 2020 as the publisher of the CAIE IGCSE Chemistry syllabus © Save My Exams Ltd. as the publisher of certain diagrams within this guide © r/IGCSE Resources 2024, authored by Veda The information on this guide has been generously prepared by current students/alumni; the authors have been acknowledged where possible. 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