In Chemistry Chapter 1 experimential Chemistry : separation techniques epure and impure substances Pure substances are made up of only one type of substance - pure substances melt and boil at fixed temperatures - - impure substances contain mixture of two or more substances impure substances melt and boil over a range - I Evaporation to dryness separates a soluble solid from a liquid to collect the solid > - > mixture is - heated strongly until all the liquid has boiled away , leaving behind the solid - suitable for solids that are heat stable of temperatures magnetic attraction + separates solids based on magnetic properties - magnetic substances will be attracted to the magnet leaving the non-magnetic substances behind , sieving > separates solids based on particle size - Finer particles can pass through the Sieve , retaining only the larger particles behind - using suitable solvents - separates solids based on solubility in the chosen solvent > solvent c - , liquid used to dissolve) is added to the mixture of solids and the insoluble solid can be removed I Distillation - separates a soluble solid from a liquid to collect the liquid -heat is applied to boil the + vapour of the liquid liquid passes through the condenser and condenses back to liquid form and is collected > soluble - impurities remain in the flask. bulb of thermometer is placed near opening of condenser > - boiling Chips are used for smooth boiling sublimation + separates solids based on the ability to sublime -heat is applied to the mixture for sublimation and its vapour changes back to solid deposit upon contact. Filtration > separates - > mixture - - an insoluble solid from a liquid is passed through a filter funnel lined with filter paper chromatography - liquid passes through the filter paper as the filtrate While the insoluble solid is retained as the residue -separates a soluble solid from a liquid to collect the liquid heated gently until as saturated solution (no more solute can dissolve - heat is removed to allow the solution to coolant crystals start to form -solid Crystals are collected - suitable for solids on the solubility in the chosen solvent -starting line is drawn in pencil to avoid smudging Crystalisation + mixture is separates liquids based by filteration that decompose upon heating(heat unstables > substances - that are more soluble travel further -substances that are less soluble travel > Once - the lesser the solvent has reached the solvent front, chromatography is complete Chemistry Chapter 2 : Kinetic particle theory the 3 states of matter gas - All matter has mass and occupies space + The 3 States of matter are solid , liquid and mass Kinetic particle theory > matter - - The is comprised of small particles , which can be atoms ,molecules or ions # particles have kinetic energy and are in constant random motion c o n te n t a t i oa n Stone a 9/09 # melting # solid liquid ⑪ Freezing Change in states exothermic process (gives offh eut) -change in state does not produce new products it is a physical state - endothermic process (requires heats Ethermal energy is either gained from or lost to the surroundings during change in state -Thermal energy is involved to either break attractive forces between particles , or form attractive forces between particles Kinetic particle theory (endothermic - As the substance is neated , thermal energy is converted to kinetic energy - When particles gain kinetic energy ,the temparature of the substance increases > When the temparature is at the - melting/boiling point all the thermal energy is used , to overcome the attractive forces between particles -this results in the change of state (from solid-liquid , liquid-gas solid-gas) and no increase in temperature is observed , > once - the state change is during state change completed ,the additional thermal energy supplied will result in the increase of temperature of the substance Kinetic particle theory (exothermic) > As - the substance is cooled , kinetic energy is converted to thermal + When the substance energy energy lose Kinetic energy the temperature of the substance decreases , -when the temperature is at the freezing / condensation point all the thermal energy is used to form the attractive forces between particles , -This results in the change of State (from liquid-solid , gas-liquid gas-solid ,and no increase in temperature is observed during state , -once the state change is completed ,the additional thermal energy lost will result in further decrease in temperature Heating and cooling curve (boiling point and melting point must write change of the substance
