FINAL EXAM

FINAL EXAM

1. CH 14: therodynamics: energy transfer between systems of particles

   • Temp: Newton's Laws of Cooling
     • 1. (change in temp)/(change in time)= (-1/current temp)(current temp-surrounding temp)
       • 2. current temp= surrounding temp + (inital temp- surrounding temp)e^(-time constant/current temp)
   • temperature scales
     • Fahrenheit, Kelvin, Celsius
       • Conversions
         • C -> K Tk=TC+273.15
           • F-> C TF=(9/5)TC+32
   • Heat: energy that flows between systems
     • SI unit: calorie, c
       • 1c=4.186 J
     • heat flows from high temp to low temp
   • Oth Law of thermodynamics
     • TA=TB=TC
   • heat capacity = Q/delta T= heat added/ temp change
     • specific heat=c=Q/m*delta temp
   • Calorimetry; used to find specific heat of system
     • Conservation of energy
       • Q=m*c*delta t
         • no phase change
       • Q=m*LF (or) LV
         • phase change

2. CH 15: Gases and Kinetic Theory

   • molecular picture of a gas
     • ex: balloon
       • contains many identical molecules
         • also applies to single atoms
     • Avogadro's number = N_A= 6.02*10^23
       • represents the number of particles in one mole
         • more precisely- # of atoms in 12 g of carbon-12
       • plays important part in connecting microscopic world with macroscopic world
     • atomic mass
       • natural sample of an element containing 1 mole of atoms
         • given in grams
         • m = M / N_A
           • m = moles
           • M = atomic mass
           • N_A = avogadro's #
   • Gas Laws
     • Avogadro's Law
       • Volume proportional to # of molecules
         • only when pressure and temp are constant
     • Boyle's Law
       • PV = constant(at constant T)
         • The constant must be proportional to the # of particles to be consistent with Avogadro's Law
     • Charles' Law
       • If T changes by delta T, volume changes by delta V
         • Applies with constant pressure
     • Gay-Lussac's Law
       • changes in pressure are proportional to changes in T
         • only for constant volume
     • Ideal Gas Law
       • PV =nRT
         • R = 8.31J/mole * K = universal gas constant
       • Boltzmann's constant= (R / N_A) = 1.38 * 10^-23 J /K = k_B
       • PV = N(k_B)T
         • N = # of gas particles
   • Kinetic Theory
     • KE = 1/2mv^2
       • KE= 3/2(k_B)T
     • v = sqroot((3k_b(T)) / m)
     • internal energy = KE_total = N(KE_trans) = 3/2 N * k_B * T = U
       • U = 3/2 n * R * T
     • Specific heat of an Ideal Gas
       • Delta U = Delta Q = 3/2 * N * k_B * Delta T
         • delta Q / delta T = 3/2 * N_A * k_B = 3/2 R
           • specific heat per mole at constant volume. denoted as C_v = 3/2R

3. CH 16: Thermodynamics

   • First Law of Thermodynamics
     • U = 3/2 * N * k_b * T
     • U = 3/2 * n * R * T
     • delta U = U_f - U_i = Q - W
       • if Q +, then delta U +
       • if Q -, then delta U -
   • calculating work
     • W = F * delta x
       • W = P * delta V
   • Thermodynamic Processes
     • Isobaric
       • constant pressure
         • W = P * delta V
     • Isothermal
       • constant temperature
         • W = nRT * ln(V_f / V_i)
     • isochoric
       • constant volume
         • W = P * delta V = 0