Chapter 12 formulas & notes Flashcards
Atomic mass #
of protons + # of neutrons
Mole
measurement for number of atoms in a particle; 1 mole = 6.02x10^23 atoms
Number of moles
n = N/Na; n=# of moles, N = number of particles, Na= Avogadro’s number
Molar mass
mass in grams of 1 mole of a substance
atomic mass unit example
12C= 12u ; “u” is atomic mass unit and C is carbon
Molar mass to moles formula
n=M (in grams)/Mmol
Boltzmann’s constant
1.38 x 10^-23
Etherm of Ideal gas
Eth= 3/2N (Kb) (delta T) ; Kb- Boltzmann’s constant
Molecular speed
Kavg= 1/2m(v^2 avg)
Root-mean square
v(rms)= sq rt (v^2)avg; or v(rms)= sq rt (3KbT/m)
Pressure
p=F/A; Force/Area
Pascal units
N/m^2
1 atm
101.3 kPa
Gage pressure
p(gage)= p - p(atmos)
Ideal Gas law formula
pV= nRT ; R is constant 8.31 J/mol K
Ideal Gas processes (quantity of gas if fixed)
p(i)V(i)/T(i) = p(f)V(f)/T(f)
Isobaric process
constant pressure process
Isothermic process
constant temp process
Isochoric process
constant volume process
Thermodynamics of Ideal Gas (work)
Wgas= p(delta V)
Adiabatic process
heat is not transferred; expansion: delta Eth = Q-Wgas; compression: delta Eth= Q + Wgas
Volume thermal expansion
delta V = beta Vi (delta T); beta is coefficient of volume expansion
Linear thermal expansion
delta L = & Li (delta T); & = coefficient of linear expansion
Specific heat
Q = Mc(delta T); M- mass, c- specific heat,
Heat of Transformation (phase changes)
Q=ML
Specific heat of gas- constant volume process
Q= nCv(delta T)
Specific heat of gas- constant pressure process
Q= nCp (delta T)
Calorimetry
Qnet= Q1 + Q2 = 0; remember change in temp and heat are negative for any system where there is a temp decrease.
Calorimetry temperature change
Q(of delta T)= Mc(Tf-Ti)
Calorimetry phase change
Q(of phase change)= +-ML
Total Calorimetry heat change
Qnet = Q(sub T) + Q (phase)
