IGCSE Chemistry States of Matter PDF

IGCSE CHEMISTRY STATES OF MATTER  Section 1 Principles of The IGCSE Chemistry Chemistry Section 2 Chemistry of the course Elements Section 3 Organic Chemistry Section 4 Physical Chemistry Section 5 Chemistry in Socie...

IGCSE CHEMISTRY STATES OF MATTER  Section 1 Principles of The IGCSE Chemistry Chemistry Section 2 Chemistry of the course Elements Section 3 Organic Chemistry Section 4 Physical Chemistry Section 5 Chemistry in Society  a) States of matter Section 1 b) Atoms c) Atomic structure Principles of d) Relative formula mass Chemistry e) Chemical formulae and chemical equations f) Ionic compounds g) Covalent substances h) Metallic crystals i) Electrolysis  1.1 understand the arrangement, movement and Lesson 1 energy of the particles in each of the three a) States of states of matter: solid, liquid matter and gas 1.2 describe how the interconversion of solids, liquids and gases are achieved and recall the names used for these interconversions 1.3 describe the changes in  What’s the difference? Solids Liquids Gases Shape Can you pour? Can you stir? Can you squash?  What’s the difference? Solids Liquids Gases Shape Fixed Can be No shape changed Can you No Yes Yes? pour? Can you stir? No Yes Yes? Can you No Yes? Yes squash? Changes of State Ga s Liq uid Soli d  Changes of State Ga s Liq { uid melti ng Soli d  Changes of State Ga { Boiling s (evaporati ng) Liq { uid melti ng Soli d  Changes of State Ga { } Boiling s (evaporati conden ng) sing Liq { uid melti ng Soli d  Changes of State Ga { } s Boiling conden (evapor sing Liq ating) { uid melti ng } freezin g Soli d  SUBLIMATIO N HEAT IS ABSORBED(ENERGY) HEAT IS RELEASED (ENERGY)  DRY ICE (CO2) Changes of State Ga s Liq uid Particles are fixed in Soli place and cannot move d Changes of State Ga s Particles are free to move Liq within a container uid Particles are fixed in Soli place and cannot move d Changes of State Particles are free to Ga move about s Particles are free to move Liq within a container uid Particles are fixed in Soli place and cannot move d  SOLIDS Strong forces of attraction held in fixed position lattice arrangement don’t move, so have definite shape and volume vibrate  SOLIDS as they become hotter, the particles vibrate more. so they expand can’t be compressed generally very dense Particle Movement EXAMPLE  SOLIDS when heated, molecules gain energy. they vibrate more and more strong forces are overcome, molecules start to move = MELTED  LIQUIDS Some attraction between molecules. free to move no definite shape, but take shape of container molecules in constantly random motion  LIQUIDS when heated, they move faster and expand can’t be compressed quite dense  Liquids Particle Movement Examples 25  LIQUIDS heat makes the molecules move faster as they gain energy. fast moving molecules at the surface will overcome forces of attraction and escape = EVAPORATION  GASES no force of attraction free to move, travel in straight lines sometimes collide no definite shape or volume, expand to fill space  GASES exert pressure on wall of container constantly moving randomly move faster when heated can be compressed very low densities  Gases Particle Movement Examples 29  GASES when heated enough, molecules have enough speed and energy to overcome forces and escape each other. molecules break away in big bubbles of gas = BOILING  The effects of temperature and pressure on the volume of a gas As the temperature of a solid, liquid or gas increases, the particles move more rapidly. As the HEAT is temperature given falls, the particles slow down. If a liquid is the pressure of the gas is inversely proportional to the volume of the gas. When the pressure increases, the gas may convert into a liquid, and on If Volume pressure further of the gas increasing the pressure, it States of Matter: Basics (c olorado.edu ) What is a pure substance ? A pure substanc ONLY e consists PURE of only one SUBSTA substanc NCES e without HAVE any IRON WATE contamin DEFINIT ant. R E BOILING Melting point 1538 °C Melting point 0 °C AND Boiling point 2862 °C Boiling point 100 °C Mixtures Do Not Have Definite Melting And Boiling Point Because They Are Not Pure Substances HOW ABOUT STONE S and soil , Do they have a definite boiling and melting points ? melting point is the temperature at which a solid changes into a liquid. boiling point is the temperature at which a liquid changes into a gas. Evaporation When a liquid changes into a gas. Evaporation occurs only at the surface of liquids where high energy particles can escape from the liquid’s surface at low temperatures, below the boiling point of the liquid. Freezing Freezing is when a liquid changes into a solid hence the melting point and freezing point of a pure substance are the same. Water for example freezes and melts at 0ºC  Heating Curve F Boilin Ga Temperature g s D point E Liqui Liq d Meltin uid +Gas g B point C Solid +Liquid Soli d A Time BC=Melting point DE=Boiling point Heating & cooling curve for water with interconversions of state  Cooling Ga Temperature s Condens ing Liq uid Freezing Soli d Time ASSIGNMENT  Lesson 2 1.4 describe simple experiments leading a) States of to the idea of the matter small size of b) Atoms particles and their movement including: i dilution of coloured solutions ii diffusion experiments  Evidence of particles Particles are very, very small, but what evidence do we have that they actually exist? Two simple experiments help us to prove their existence: 1. Dilution of coloured solutions 2. Diffusion experiments Evidence of particles – diffusion experiments Spray air freshener in the corner of a room Evidence of particles – diffusion experiments Particles spread out in all directions Evidence of particles – diffusion experiments Eventually the particles occupy the whole room  Evidence of particles – diffusion experiments Other examples of diffusion include: Smell of frying bacon from a kitchen Leaking of air from inside a balloon Evidence of particles – diffusion experiments  Evidence of particles – diffusion experiments Diffusion is the movement of particles from areas of high Diffusion is slower in concentration to areas of low LIQUIDS than in GASES concentration until they are evenly because liquid particles are not spread. Diffusion depends upon the as free to move as gas particles. random movement of particles. Diffusion does not take place in SOLIDS TEMPERATURES NH3(AM HCl(Hydro ONIA) , chloric MASS is acid) , 17 MASS is 36.5 NH3 (g) + HCl (g) → NH4Cl (s) NH3 molecules have less mass than the HCl molecule, so diffuse faster, hence the product (a white cloud of NH4Cl) forms closer to the end where the HCl is Diffusion (colorado.ed u)