813.1 Some important concepts 1=0K is called absolute zero One Kelvin is defined to be 1273.16 of the temperature of the triple point of water. Ideal gas temperature scale: T=273.16K(lim +0P T=telsius +273.15 (K) 813.2 Heat transfer and calorimetry 1. Heat and heat transfer Heat is energy that flow between a system and its environment simply because of the difference of temperature between them Characteristic: Othe process of heat transfer continues until the both systems reach to thermal equilibrium (have same temperature); @heat transfer occurs from the hotter system to the cooler system; Cheat transfer is essentially a microscopic atom-to-atom transfer of energy, it is distinctly different from macroscopic wok 6
6 T=0K is called absolute zero. One Kelvin is defined to be 1/273.16 of the temperature of the triple point of water. Ideal gas temperature scale: 273.16K( lim ) 3 gas 0 P P T → = 273.15 (K) T = tcelsius + §13.1 Some important concepts §13.2 Heat transfer, and calorimetry 1. Heat and heat transfer Heat is energy that flow between a system and its environment simply because of the difference of temperature between them. Characteristic: 1the process of heat transfer continues until the both systems reach to thermal equilibrium (have same temperature); 2heat transfer occurs from the hotter system to the cooler system; 3heat transfer is essentially a microscopic atom-to-atom transfer of energy, it is distinctly different from macroscopic wok
813.2 Heat transfer and calorimetry Environment T Environment T Environment 1>7 <0 R=l r< 2<0, heat transfer from a system; 0>0, heat transfer to a system 2. Temperature change and specific heat do Experiment:dT∝ do= cmdT I do specific heat J/kg. KI m dT 813.2 Heat transfer and calorimetry do= cmdT= ncmolar dT I do molar=---molar specific heat J/molK n dT Molar specific heat is the heat transfer to one mole of the material needed to raise it temperature by one Kelvin do do For gases: Cy m dT dT Molars do do n dT molar p dT
7 Q < 0, heat transfer from a system; Q > 0, heat transfer to a system. 2. Temperature change and specific heat Experiment: m Q T d d ∝ dQ = cmdT T Q m c d 1 d = --specific heat [J/kg·K] §13.2 Heat transfer, and calorimetry dQ = cmdT = ncmolardT T Q n c d 1 d molar = --molar specific heat[J/mol·K] Molar specific heat is the heat transfer to one mole of the material needed to raise it temperature by one Kelvin. V V T Q m c ) d d ( 1 For gases: = P P T Q m c ) d d ( 1 = V T Q n c ) d d ( 1 molar V = P T Q n c ) d d ( 1 molar P = §13.2 Heat transfer, and calorimetry