Chapter 2.1 Heat Work & Energy

(2.1) heat, work & energy what is thermodynamics Study of energy involved in physical & chemical changes systems & surroundings →heat flows from the warmer object to the cooler objects a a ystem is the reaction & the surroundings are the environment/ vessel system types of systems 0 open system: matter is energy exchange wl surroundings closed system changes w/ surroundings energy exchanges isolated system: doesn't exchange matter or energy exchange energy w/ surroundings what is energy? the capacity to do work. (w= F.d.) distance (Jor Nim) (KPL) Some types of energy ode L. heat energy (thermal energy), energy kansiered due to temp dil blw system & surroundings Le Kinchic energy energy, energy associated w/motion Lo potential energy, stored energy or energy a body possesses due to its position Lo chemical energy is a form of potential energy units of energy (J-joule) → heat energy associated w/ temp changes can be estimated using heat capacity heat capacity & its uses →heat flow contimes blw objects until thermal equilibrium 9= CAT 9-MCAT heat transfervsd temp diff mass spesifis heat MASS capacity objects heat capacity temperature change ENDOTHERMIC absorbs energy from surroundings (+ positive) system heats EXOTHERMIC releases energy to surroundings (negative) system cools thermal equilibrium →Warmer object cools down; \(\Delta T<0\) ; \[g_{inal}=-\] cooler object warms up: \(\Delta T>0\) ; qgened + -9lost agained intensive & extensive properties → intensive (intrinsic) property same value regardless of the sample size temp, density extensive (extrinsic) property: physical property whove radne increases il sample see mass, vol, energy, enthalpy, entropy Stare functions → property whose valine depends on only the current state of the system not on how that state was reached but volume, pressure, enthalpy NOT heat & work first law of thermodynamics the total ener energy of an isolated system is conserved system internal energy (E) sum of all kinetic & potential energias in the system. in expansion, system does work on Surroundings (w is negative), \[(\Delta E>0)\] are doing work on the system (wis positive) (460) → in compression, surroundings are doing Lit a process doesn't involve compression/expansion, there's no \((\Delta v=0)\) & the value of w is zero volume change heat B \[\Delta E=q+w\] work are equivalent ways of transform \[\Delta E=qr2\] transforming energy → the internal energy change of a system is Signifies that relume of equal to the heat transferred when the the system remains volume does not change Contfan Internal Energy,