ChemActivity 5: Phase Diagrams How are the effects of temperature and pressure on phase transitio Prerequisite Knowledge: 1) Describe solid, liquid and gas states at the particula Predict the effect of temperature and pressure on solids, liquids and gases. Learning objective: 1.9 Interpret phase diagrams. Model 1: Phase Diagrams A phase diagram is a graphical way to represent the effects of temperature and p phase of a substance. The curves indicate a set of temperatures and pressures where the phases exist i between the two states on opposite sides of the line. For example, for r any point on this I (temperature and both the solid and Critical Bpoint 425 atm Liquid Melting The vapor pressu the critical point temperature and which the gas car The liquid and ga longer exist sepa supercritical flu the liquid and ga comingled. Freezing Solid Vaporization Condensation 1 atm Gas 0.010atm -A, Triple poigt Sublimation Deposition The triple point of temperature a where all three p equilibrium. 89 -55-32 515 Temperature tC Various pressure used. Recall: 1 atm = 101.3 H Iden Idens Key Questions 1) What are the conditions of STP (Standard Temperature and Pressure)? and 273.15K 1 atm 2) What is the normal boiling point of the compound? You will need to recall wi means with regards to phase changes to answer this questinn and the nAYt Pressure 4) Describe the equilibrium that exists along curve AB at the particulate level. What does it mean to be "at equilibrium" in this context? The particles 5) What are the conditions of temperature and pressure for the triple point? The triple point is the condition of Hemperarure oavilibrmre where ale thyee pnases exist. at and 89oc. yee phases 1 authm equilibriuM:This ocCurs at 6) What are the conditions for the critical point? The critical point is and pressure above Mich the liquified. ThIS occurs at 425 atmo and S1S°C. the terriperature gas Cann.0 7) At a constant pressure of 0.001 atm, what phase transition(s) occur(s) as the temperature is increased from -273 to 500 °C? 8) At a constant pressure of 5 atm, what phase transition(s) occur as the temperature is increased from -273 to 500 °C.? ha r 9) At a constant temperature of 70°C, what phase transition(s) occur(s) as the pressure in increased? 21 3eing 10) Examine the fusion (freezing-melting) curve. As pressure is increased, which state is favored, liquid or solid? The liquid state is favored. Ine Ismontotew d nooun kon arb bns nodzbup on orh Sbuogmo Ismon adu 2.