vapour pressure, phase changes, solution Flashcards
vapour pressure
the pressure above a liquid or sometimes solid as a result of some molecules breaking bonds and escaping before boiling.
Relationship between vapour pressure and temperature
As temperature increases, the vapour pressure increases which also means that as kinetic energy increases, vapour pressure increases
when does boiling occur?
Boiling occurs when the vapour pressure is the same as the atmospheric pressure
Exothermic
creates intermolecular bonds by removing heat from the system. q<0
Endothermic
disrupts bonds by adding heat to the system. q>0
Phase diagram
a diagram that plots temperature against pressure and shows when phase changes occur for different substances
sublimation
phase change from solid to gas
deposition
phase change from gas to solid
condensation
phase change from gas to liquid
fusion
phase change from solid to liquid
vaporization
phase change from liquid to gas
triple point
point where solid, liquid, and gas are present
critical point
point where supercritical fluid occurs
molar heat capacity
amount of heat required to heat 1 mole of water by 1 degree celsius
Formula for warming ice, water, or gas
q = nCp(Tf-Ti)
Formula for phase change
q = n*change in heat of vaporization or fusion
Total heat for changing ice to vapor
add heat from each phase
heat to warm ice + heat to melt + heat to warm water + heat to vaporize + heat to warm gas
Clasius-Clapeyron equation
it is used to determine the enthalpy of vaporization when given vapour pressures at different temperatures. The equation is ;
ln(P1/P2) = - deltaHvap/R (1/T1-1/T2)
Relationship between heat of vaporization and intermolecular force strength
The stronger the intermolecular force would require more heat to vaporize.
solute
minor component of solution
solvent
major component of solution
solution
homogenous mixture of solute and solvent
