Key Terms
Celsius
Freezing at 0 C, boiling at 100 C. 100 degrees span the full water range.
Fahrenheit
Freezing at 32 F, boiling at 212 F. 180 degrees span the same range.
Kelvin
Absolute scale. 0 K = absolute zero.
Thermal equilibrium
Two objects in contact with no heat flow between them. They are the same temperature.
Zeroth Law of Thermodynamics
If A is in thermal equilibrium with B, and B is in thermal equilibrium with C, then A is also in thermal equilibrium wit
Formula
Delta-L = alpha x L-initial x delta-T
Area expansion
Delta-A = 2 x alpha x A-initial x delta-T
Volume expansion
Delta-V = beta x V-initial x delta-T Where beta = 3 x alpha for solids.
Examples
Railroad track buckling on hot days, power lines snapping in cold, glass cracking from rapid uneven cooling.
Molar mass
The mass in grams of one mole equals the molecular weight from the periodic table.
If volume is constant
P1/T1 = P2/T2 If pressure is constant: V1/T1 = V2/T2 (Charles's Law) If temperature is constant: P1V1 = P2V2 (Boyle's La
Derived equation
PV = (1/3) x N x m x v-squared-average
Average translational kinetic energy per molecule
KE-avg = (3/2) x k x T
Or equivalently
V-rms = sqrt(3RT / M)
Critical point
The temperature and pressure above which liquid cannot exist as a distinct phase. Above the critical temperature, no amo